Tue Dec 29 22:28:23 UTC 2009 John S. Kinnebrew <john.s.kinnebrew@vanderbilt.edu>

18 files changed, 1683 insertions, 449 deletions

diff --git a/SA_POP/ChangeLog b/SA_POP/ChangeLog
index 8803fed21b2..97d4655fee6 100644
--- a/SA_POP/ChangeLog
+++ b/SA_POP/ChangeLog
@@ -1,3 +1,40 @@
+Tue Dec 29 22:28:23 UTC 2009  John S. Kinnebrew  <john.s.kinnebrew@vanderbilt.edu>
+
+        * UserInput:
+        * UserInput/InputCL.h:
+        * UserInput/InputCL.cpp:
+        * UserInput/Question.h:
+        * UserInput/Question.cpp:
+
+          Added reusable text user interface.
+
+
+        * Standalone/SAPOP_Demo.mpc:
+        * Standalone/SA_POP_Demo.cpp:
+
+          Updated SA-POP Standalone to use new UI.
+
+
+        * Standalone/UserInput.h:
+        * Standalone/UserInput.cpp:
+
+          Removed these old UI files.
+
+
+        * Planner.cpp:
+        * SA_POP_Types.h:
+        * SANet/SANet.h:
+        * SANet/SANet.cpp:
+        * SANet/SANet_Standalone.mpc:
+        * SANet/SANet_Types.h:
+        * SANet/SANet_UI.cpp:
+        * SANet/SANode.h:
+        * SANet/SANode.cpp:
+
+          Added SANet cloning (deep copy by copy constructor).
+          Also cleaned up some more of the SANet code.
+          
+
 Fri Dec 18 20:28:36 UTC 2009  John S. Kinnebrew  <john.s.kinnebrew@vanderbilt.edu>
 
         * SA_POP_Types.h:
@@ -22,8 +59,8 @@ Fri Dec 18 01:00:33 UTC 2009  John S. Kinnebrew  <john.s.kinnebrew@vanderbilt.ed
         * SA_Builder.h:
         * SA_Builder.cpp:
 
-          Updated initialization of SA_Builder so overridden init()
-          method will work correctly.
+          Updated initialization of SA_Builder so overriding init()
+          method will work correctly in derived classes.
 
 
         * SAPOP_Exp_EU.mwc:
@@ -42,7 +79,6 @@ Fri Dec 18 01:00:33 UTC 2009  John S. Kinnebrew  <john.s.kinnebrew@vanderbilt.ed
           Added EU performance experiment skeleton.
 
 
-
         * experiments/EU_Test:
         * experiments/EU_Test/EU_Test.mpc:
         * experiments/EU_Test/EU_Test.cpp:
diff --git a/SA_POP/Planner.cpp b/SA_POP/Planner.cpp
index 1862d015a70..89c3c1709a3 100644
--- a/SA_POP/Planner.cpp
+++ b/SA_POP/Planner.cpp
@@ -525,9 +525,6 @@ double Planner::calculate_plan_utility(size_t sa_max_steps)
 
 		this->sanet_->set_task_state(this->working_plan_->get_task_from_inst((*it).second), true);
 		this->sanet_->set_cond_state((*it).cond.id, true);
-//		this->sanet_->note_causal_link(*it);
-		
-
 
 		std::cout<<(*it).cond.id<<" cond, "<<(*it).first<<" first, "<<(*it).second<<" second"<<std::endl;
 
@@ -540,15 +537,18 @@ double Planner::calculate_plan_utility(size_t sa_max_steps)
 		this->sanet_->set_cond_state(it->first, true);
 	}
 
-//	sanet_->restrict_prop_to_clinks(true);
 	sanet_->update(sa_max_steps);
-//	sanet_->restrict_prop_to_clinks(false);
 
 	double conj_utils = 0;
 	for(GoalMap::iterator it = goals.begin(); it != goals.end(); it++){
 		std::cout<<it->second<<std::endl;
-		std::cout<<this->sanet_->get_cond_future_val(it->first, this->sanet_->get_step())<<std::endl;
-		conj_utils+=(it->second * this->sanet_->get_cond_future_val(it->first, this->sanet_->get_step()));
+    if (it->second >= 0.0) {
+		  std::cout<<this->sanet_->get_cond_future_val(it->first, true)<<std::endl;
+		  conj_utils+=(it->second * this->sanet_->get_cond_future_val(it->first, true));
+    } else {
+		  std::cout<<this->sanet_->get_cond_future_val(it->first, false)<<std::endl;
+		  conj_utils+=(it->second * this->sanet_->get_cond_future_val(it->first, false));
+    }
 	}
 
 	std::cout<<"Plan utility: "<<conj_utils<<std::endl;
diff --git a/SA_POP/SANet/SANet.cpp b/SA_POP/SANet/SANet.cpp
index 07cabb4066f..93883aaad50 100644
--- a/SA_POP/SANet/SANet.cpp
+++ b/SA_POP/SANet/SANet.cpp
@@ -17,16 +17,14 @@
 #include "SANet.h"
 #include "SANode.h"
 #include "SANet_Exceptions.h"
-#include "SA_POP_Types.h"
 
 using namespace SANet;
 
 
 SANet::Network::Network (void)
 : step_ (0)
-//, restrict_prop_to_clinks_(false)
 {
-  // Clear maps & sets.
+  // All map/set member variables initially empty.
   this->task_nodes_.clear ();
   this->cond_nodes_.clear ();
   this->precond_links_.clear ();
@@ -36,14 +34,104 @@ SANet::Network::Network (void)
   this->disabled_tasks_.clear ();
   this->active_conds_.clear ();
   this->disabled_conds_.clear ();
-//  this->causal_links_by_first_.clear ();
-//  this->causal_links_by_cond_.clear ();
-//  this->causal_links_by_second_.clear ();
 };
 
-int SANet::Network::get_step(){
-	return step_;
-}
+
+// Copy constructor. Performs initialization by making a deep copy
+// of the provided network (including allocation of new nodes with
+// state copied from nodes in provided network and creation of
+// corresponding links between them).
+SANet::Network::Network (const Network &s)
+: step_ (s.step_)
+{
+  // Member variables that include node pointers are initially empty.
+  this->task_nodes_.clear ();
+  this->cond_nodes_.clear ();
+
+  // Member variables that include links are initially empty (will be populated during link creation).
+  this->precond_links_.clear ();
+  this->effect_links_.clear ();
+
+  // Copy active/disabled node (ID) sets (no node pointers and no links).
+  this->active_tasks_ = s.active_tasks_;
+  this->disabled_tasks_ = s.disabled_tasks_;
+  this->active_conds_ = s.active_conds_;
+  this->disabled_conds_ = s.disabled_conds_;
+
+  // Copy goals (no node pointers and no links).
+  this->goals_ = s.goals_;
+
+  // Create new nodes corresponding to those in s, adding each to appropriate node (ID to pointer) map.
+  for (TaskNodeMap::const_iterator node_iter = s.task_nodes_.begin ();
+    node_iter != s.task_nodes_.end (); node_iter++)
+  {
+    SANet::TaskNode *new_node = new SANet::TaskNode (*(node_iter->second));
+    this->task_nodes_.insert (std::make_pair (node_iter->first, new_node));
+  }
+  for (CondNodeMap::const_iterator node_iter = s.cond_nodes_.begin ();
+    node_iter != s.cond_nodes_.end (); node_iter++)
+  {
+    SANet::CondNode *new_node = new SANet::CondNode (*(node_iter->second));
+    this->cond_nodes_.insert (std::make_pair (node_iter->first, new_node));
+  }
+
+  // Create precondition links corresponding to all those in s
+  // (using pointers to new nodes instead of the original nodes in s).
+  for (PrecondLinkPortMap::const_iterator link_iter = s.precond_links_.begin ();
+    link_iter != s.precond_links_.end (); link_iter++)
+  {
+    PrecondLink link = link_iter->first;
+    PortID port = link_iter->second;
+
+    // Get pointer to task node in original network.
+    TaskNodeMap::const_iterator orig_task_iter = s.task_nodes_.find (link.second);
+    if (orig_task_iter == s.task_nodes_.end ())
+      throw UnknownNode ();
+    TaskNode *orig_task = orig_task_iter->second;
+
+    // Get precondition link conditional probabilities.
+    ConditionalProb prob = orig_task->get_precond_prob (link.first);
+
+    // Add precondition link.
+    this->add_precond_link (link.first, link.second, prob.true_prob, prob.false_prob, port);
+  }
+
+  // Create effect links corresponding to all those in s
+  // (using pointers to new nodes instead of the original nodes in s).
+  for (EffectLinkPortMap::const_iterator link_iter = s.effect_links_.begin ();
+    link_iter != s.effect_links_.end (); link_iter++)
+  {
+    EffectLink link = link_iter->first;
+    PortID port = link_iter->second;
+
+    // Get pointer to task node.
+    TaskNodeMap::const_iterator orig_task_iter = s.task_nodes_.find (link.first);
+    if (orig_task_iter == s.task_nodes_.end ())
+      throw UnknownNode ();
+    TaskNode *orig_task = orig_task_iter->second;
+
+    // Get effect link probability.
+    Probability prob = orig_task->get_effect_prob (link.second);
+
+    // Add effect link.
+    this->add_effect_link (link.first, link.second, prob, port);
+  }
+
+// Network data members
+    // STRUCTURE VARIABLES.
+//    TaskNodeMap task_nodes_;
+//    CondNodeMap cond_nodes_;
+//    PrecondLinkPortMap precond_links_;
+//    EffectLinkPortMap effect_links_;
+    // STATE VARIABLES.
+//    TaskIDSet active_tasks_;
+//    TaskIDSet disabled_tasks_;
+//    CondIDSet active_conds_;
+//    CondIDSet disabled_conds_;
+//    GoalMap goals_;
+//    int step_;
+};
+
 
 SANet::Network::~Network ()
 {
@@ -62,10 +150,6 @@ SANet::Network::~Network ()
   }
 };
 
-//void SANet::Network::restrict_prop_to_clinks(bool val){
-//	restrict_prop_to_clinks_ = val;
-//};
-
 void SANet::Network::add_task (TaskID ID, std::string name, MultFactor atten_factor,
                           TaskCost cost, Probability prior_prob)
 {
@@ -104,40 +188,6 @@ void SANet::Network::reset_step(){
 }
 
 
-/*
-void SANet::Network::note_causal_link(SA_POP::CausalLink clink){
-	causal_links_by_first_.insert(std::pair<TaskID, SA_POP::CausalLink> (clink.first, clink));
-	causal_links_by_cond_.insert(std::pair<CondID, SA_POP::CausalLink> (clink.cond.id, clink));
-	causal_links_by_second_.insert(std::pair<TaskID, SA_POP::CausalLink> (clink.second, clink));
-}
-
-bool SANet::Network::is_clink_first_to_cond_by_first(TaskID task, CondID cond){
-
-	for(std::multimap<SANet::TaskID, SA_POP::CausalLink>::iterator it = causal_links_by_first_.lower_bound(task); 
-		it != causal_links_by_first_.upper_bound(task); it++){
-			SA_POP::CausalLink clink = it->second;
-		if(clink.cond.id == cond){
-			return true;
-		}
-	}
-
-	return false;
-}
-
-bool SANet::Network::is_clink_first_to_cond_by_cond(CondID cond, TaskID task){
-	for(std::multimap<SANet::CondID, SA_POP::CausalLink>::iterator it = causal_links_by_cond_.lower_bound(task);
-		it != causal_links_by_cond_.upper_bound(cond); it++){
-			SA_POP::CausalLink clink = it->second;
-
-			if(clink.first == task){
-				return true;
-			}
-	}
-
-	return false;
-}
-*/
-
 Probability SANet::Network::get_prior(TaskID ID)
 {
   TaskNodeMap::iterator task_iter = task_nodes_.find (ID);
@@ -536,13 +586,24 @@ Probability SANet::Network::get_cond_val (CondID cond_id)
   return iter->second->get_init_prob ();
 };
 
-Probability SANet::Network::get_cond_future_val(CondID cond_id, int step){
+// Get a condition's future probability for a given value.
+// (NOTE: Future probability is based on whatever spreading
+// activation has already been executed.)
+
+//****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****
+// (WARNING: Condition node must have been active for all
+// spreading activation or exception will be thrown.)
+//****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****
+
+Probability SANet::Network::get_cond_future_val(CondID cond_id, bool value)
+{
 	CondNodeMap::iterator iter = this->cond_nodes_.find(cond_id);
 	if(iter == this->cond_nodes_.end())
-		throw "SANet::Network::get_cond_val (): Unknown condition node.";
-	return iter->second->get_prob (step).probability;
+		throw "SANet::Network::get_cond_future_val (): Unknown condition node.";
+	return (iter->second->get_prob (this->step_, value)).probability;
 }
 
+
 // Get all goals.
 const GoalMap& SANet::Network::get_goals (void)
 {
@@ -665,12 +726,21 @@ CondSet SANet::Network::get_effects (TaskID task_id)
   return effects;
 };
 
+
+
+// ****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP
+// Ankit's function get_duration() needs to be removed, once we ensure any
+// scheduling code relying on it has been changed.
+
 // Get the duration of a task.
 TimeValue SANet::Network::get_duration (TaskID task_id)
 {
 	TaskNode *temp = this->task_nodes_.find(task_id)->second;
   return NULL_TIME;
 }
+// ****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP
+
+
 
 // Get all tasks that satisfy a condition.
 TaskSet SANet::Network::get_satisfying_tasks (Condition cond)
@@ -739,98 +809,89 @@ LinkPorts SANet::Network::get_clink_ports (TaskID task1_id, CondID cond_id,
 // Set Task State.
 void SANet::Network::set_task_state(TaskID task_ID, bool state)
 {
-
-    task_nodes_.find(task_ID)->second->set_activity(state);
-
-    if(state)
-    {
-      //insetr into active, remove from disabled
-      this->active_tasks_.insert(task_ID);
-
-      this->disabled_tasks_.erase(task_ID);
-
-    }
-    else
-    {
-      //remove from active, insert into disabled
-
-      this->active_tasks_.erase(task_ID);
-
-      this->disabled_tasks_.insert(task_ID);
-    }
+  // Get pointer to node from ID.
+  SANet::TaskNodeMap::iterator task_iter = this->task_nodes_.find(task_ID);
+  if (task_iter == this->task_nodes_.end ())
+    throw UnknownNode ();
+  
+  // Use node pointer to set activity state.
+  task_iter->second->set_activity(state);
+
+  if(state) {
+    // Insert into active task set & remove from disabled task set.
+    this->active_tasks_.insert(task_ID);
+    this->disabled_tasks_.erase(task_ID);
+  } else {
+    // Remove from active task set & insert into disabled task set.
+    this->active_tasks_.erase(task_ID);
+    this->disabled_tasks_.insert(task_ID);
+  }
 };
 
 // Set Cond State.
 void SANet::Network::set_cond_state(CondID cond_ID, bool state)
 {
     
-    cond_nodes_.find(cond_ID)->second->set_activity(state);
-    if(state)
-    {
-      //insetr into active, remove from disabled
-      this->active_conds_.insert(cond_ID);
-
-
-      this->disabled_conds_.erase(cond_ID);
-
-    }
-    else
-    {
-      //remove from active, insert into disabled
+  // Get pointer to node from ID.
+  SANet::CondNodeMap::iterator cond_iter = this->cond_nodes_.find(cond_ID);
+  if (cond_iter == this->cond_nodes_.end ())
+    throw UnknownNode ();
+  
+  // Use node pointer to set activity state.
+  cond_iter->second->set_activity(state);
 
-      this->active_conds_.erase(cond_ID);
+  if(state) {
+    // Insert into active condition set & remove from disabled condition set.
+    this->active_conds_.insert(cond_ID);
+    this->disabled_conds_.erase(cond_ID);
 
-      this->disabled_conds_.insert(cond_ID);
-    }
+  } else {
+    // Remove from active condition set & insert into disabled condition set.
+    this->active_conds_.erase(cond_ID);
+    this->disabled_conds_.insert(cond_ID);
+  }
 
 };
 
 // Set All nodes to State.
 void SANet::Network::set_nodes_state(bool state)
 {
-    if(state)
+  if(state) {
+    // For all tasks, activate, insert into active set, & remove from disabled set.
+    for (TaskNodeMap::iterator node_iter = task_nodes_.begin ();
+    node_iter != task_nodes_.end (); node_iter++)
     {
+      node_iter->second->set_activity(state);
+      this->active_tasks_.insert(node_iter->first);
+      this->disabled_tasks_.erase(node_iter->first);
+    }
 
-      //insetr all tasks into active, remove from disabled
-      for (TaskNodeMap::iterator node_iter = task_nodes_.begin ();
-      node_iter != task_nodes_.end (); node_iter++)
-      {
-        node_iter->second->set_activity(state);
-        this->active_tasks_.insert(node_iter->first);
-
-        this->disabled_tasks_.erase(node_iter->first);
-      }
-
-      for (CondNodeMap::iterator node_iter = cond_nodes_.begin ();
-      node_iter != cond_nodes_.end (); node_iter++)
-      {
-        node_iter->second->set_activity(state);
-        this->active_conds_.insert(node_iter->first);
-
-        this->disabled_conds_.erase(node_iter->first);
-      }
+    // For all conditions, activate, insert into active set, & remove from disabled set.
+    for (CondNodeMap::iterator node_iter = cond_nodes_.begin ();
+    node_iter != cond_nodes_.end (); node_iter++)
+    {
+      node_iter->second->set_activity(state);
+      this->active_conds_.insert(node_iter->first);
+      this->disabled_conds_.erase(node_iter->first);
     }
-    else
+  } else {
+    // For all tasks, deactivate, remove from active set, & insert into disabled set.
+    for (TaskNodeMap::iterator node_iter = task_nodes_.begin ();
+         node_iter != task_nodes_.end (); node_iter++)
     {
-      //remove from active, insert into disabled
-
-      for (TaskNodeMap::iterator node_iter = task_nodes_.begin ();
-      node_iter != task_nodes_.end (); node_iter++)
-      {
-        node_iter->second->set_activity(state);
-        this->active_tasks_.erase(node_iter->first);
-
-        this->disabled_tasks_.insert(node_iter->first);
-      }
-
-      for (CondNodeMap::iterator node_iter = cond_nodes_.begin ();
-      node_iter != cond_nodes_.end (); node_iter++)
-      {
-        node_iter->second->set_activity(state);
-        this->active_conds_.erase(node_iter->first);
+      node_iter->second->set_activity(state);
+      this->active_tasks_.erase(node_iter->first);
+      this->disabled_tasks_.insert(node_iter->first);
+    }
 
-        this->disabled_conds_.insert(node_iter->first);
-      }
+    // For all conditions, deactivate, remove from active set, & insert into disabled set.
+    for (CondNodeMap::iterator node_iter = cond_nodes_.begin ();
+         node_iter != cond_nodes_.end (); node_iter++)
+    {
+      node_iter->second->set_activity(state);
+      this->active_conds_.erase(node_iter->first);
+      this->disabled_conds_.insert(node_iter->first);
     }
+  }
 
 };
\ No newline at end of file
diff --git a/SA_POP/SANet/SANet.h b/SA_POP/SANet/SANet.h
index ef49ed94473..b50318b17d5 100644
--- a/SA_POP/SANet/SANet.h
+++ b/SA_POP/SANet/SANet.h
@@ -17,12 +17,16 @@
 #include <iostream>
 #include <map>
 #include <set>
-#include <stdexcept>
 #include "SANet_Types.h"
 #include "SANode.h"
-#include "SA_POP_Types.h"
 
 namespace SANet {
+  /// Set of task node IDs.
+  typedef std::set<TaskID> TaskIDSet;
+
+  /// Set of condition node IDs.
+  typedef std::set<CondID> CondIDSet;
+
   /// Map from task node ID to pointer.
   typedef std::map<TaskID, TaskNode *> TaskNodeMap;
 
@@ -45,13 +49,22 @@ namespace SANet {
     /// Constructor.
     Network (void);
 
+    /// Copy constructor. Performs initialization by making a deep copy
+    /// of the provided network (including allocation of new nodes with
+    /// state copied from nodes in provided network and creation of
+    /// corresponding links between them).
+    /**
+     * @param s  Network to copy.
+     */
+    Network (const Network &s);
+
     /// Destructor.
     virtual ~Network ();
 
 
 
     // ************************************************************************
-    // Network creations methods.
+    // Network creation methods.
     // ************************************************************************
 
     /// Add a new task node to the network.
@@ -81,9 +94,9 @@ namespace SANet {
      *
      * @param false_prob  Initial probability that value is false.
      *
-     * @param cond_kind The type of condition
+     * @param cond_kind  The type of condition.
      *
-     * @param goal_util  Initial utility (positive for goals, zero otherwise).
+     * @param goal_util  Initial utility (positive for TRUE goals, negative for FALSE goals, and zero for non-goals).
      */
     virtual void add_cond (CondID ID, std::string name,
       MultFactor atten_factor, Probability true_prob, Probability false_prob,
@@ -115,35 +128,12 @@ namespace SANet {
      *
      * @param weight  Link weight (probability task sets condition to
      * true, or negative of the probability task sets condition to false).
-     *
-     * @param port_ID  ID of port (on task) associated with this condition
+     *     * @param port_ID  ID of port (on task) associated with this condition
      *                 (used for data nodes).
      */
     virtual void add_effect_link (TaskID task_ID, CondID cond_ID,
       LinkWeight weight, PortID port_ID = "");
 
-    /// Set the state of a task node.
-    /**
-     * @param task_ID  Task node ID.
-     *
-     * @param state  New state (false for inactive, and true for active);
-     */
-    virtual void set_task_state(TaskID task_ID, bool state);
-
-    /// Set the state of a condition node.
-    /**
-     * @param cond_ID  Condition node ID.
-     *
-     * @param state  New state (false for inactive, and true for active);
-     */
-    virtual void set_cond_state(CondID cond_ID, bool state);
-
-    /// Set state of all nodes.
-    /**
-     * @param state  New state (false for inactive, and true for active);
-     */
-    virtual void set_nodes_state(bool state);
-
 
 
 
@@ -163,12 +153,14 @@ namespace SANet {
     /// Print Graphviz network representation to stream.
     /**
      * @param strm  Output stream on which to print network representation.
+     *
      * @param graphmap  The color mapping being used.
+     *
      * @param defaultColor  The default color if it's not in the mapping.     
      */
-    virtual void print_graphviz (std::basic_ostream<char, std::char_traits<char> >& strm, std::map<std::string, std::string>& graphmap, std::string defaultColor = "grey");
-
-    
+    virtual void print_graphviz (std::basic_ostream<char,
+      std::char_traits<char> >& strm, std::map<std::string, std::string>& graphmap,
+      std::string defaultColor = "grey");
 
     /// Print XML network representation to stream.
     /**
@@ -226,7 +218,7 @@ namespace SANet {
      *
      * @param prior  New prior probability;
      */
-    virtual void update_prior(TaskID task_ID, Probability prior);
+    virtual void update_prior (TaskID task_ID, Probability prior);
 
     /// Update a task to condition link.
     /**
@@ -240,8 +232,30 @@ namespace SANet {
      * @param port_ID  ID of port (on task) associated with this condition
      *                 (used for data nodes).
      */
-    virtual void update_effect_link(TaskID task_ID, CondID cond_ID,
-                               LinkWeight weight, PortID port_ID= "");
+    virtual void update_effect_link (TaskID task_ID, CondID cond_ID,
+      LinkWeight weight, PortID port_ID= "");
+
+    /// Set the state of a task node.
+    /**
+     * @param task_ID  Task node ID.
+     *
+     * @param state  New state (false for inactive, and true for active);
+     */
+    virtual void set_task_state(TaskID task_ID, bool state);
+
+    /// Set the state of a condition node.
+    /**
+     * @param cond_ID  Condition node ID.
+     *
+     * @param state  New state (false for inactive, and true for active);
+     */
+    virtual void set_cond_state(CondID cond_ID, bool state);
+
+    /// Set state of all nodes.
+    /**
+     * @param state  New state (false for inactive, and true for active);
+     */
+    virtual void set_nodes_state(bool state);
 
 
 
@@ -283,6 +297,20 @@ namespace SANet {
      */
     virtual Probability get_cond_val (CondID cond_id);
 
+    /// Get a condition's future probability for a given value.
+    /// (NOTE: Future probability is based on whatever spreading
+    /// activiation has already been executed.)
+    /// (WARNING: Condition node must have been active for all
+    /// spreading activation or exception will be thrown.)
+    /**
+     * @param cond_id  Condition ID.
+     *
+     * @param value  Value for which to get condition future probability.
+     *
+     * @return  Future task expected utility.
+     */
+    Probability get_cond_future_val(CondID cond_id, bool value);
+
     /// Get all goals.
     /**
      * @return  Set of condition ids and associated utilities.
@@ -298,6 +326,8 @@ namespace SANet {
     virtual Utility get_task_current_eu (TaskID task_id);
 
     /// Get a task's future expected utility.
+    /// (NOTE: Future probability is based on whatever spreading
+    /// activiation has already been executed).
     /**
      * @param task_id  The task id.
      *
@@ -363,7 +393,7 @@ namespace SANet {
 
     /// Get the prior probability for a task node in the network.
     /**
-     * @param ID  Node ID.
+     * @param ID  ID of task node.
      *
      * @returns  Prior probability of the task.
      */
@@ -373,29 +403,27 @@ namespace SANet {
     /**
      * @param task_ID  Task ID.
      *
-     * @param cond_ID  Cond ID.
+     * @param cond_ID  Condition ID.
      *
      * @returns  Weight of the effect link.
      */
     virtual LinkWeight get_link(TaskID task_ID, CondID cond_ID);
 
+
+    // ****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP
+    // Ankit's function get_duration() needs to be removed, once we ensure any
+    // scheduling code relying on it has been changed.
+    // ****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP
+
     /// Get the duration of a task
     /**
-     * @param task_id ID of the Task
+     * @param task_id  Task ID.
      *
-     * @return duration of the task
+     * @return  Duration of the task.
      */
     virtual TimeValue get_duration (TaskID task_id);
 
 
-    Probability get_cond_future_val(int step, CondID cond_id);
-
-    int get_step();
-
-//    void note_causal_link(SA_POP::CausalLink clink);
-
-//    void restrict_prop_to_clinks(bool val);
-
 
   protected:
     // ************************************************************************
@@ -420,17 +448,17 @@ namespace SANet {
     // State variables.
     // ************************************************************************
 
-    //Set of Active Task Nodes
-    std::set<SANet::TaskID> active_tasks_;
+    /// Set of active task nodes (by ID).
+    TaskIDSet active_tasks_;
 
-    //Set of Disabled Task Nodes
-    std::set<SANet::TaskID> disabled_tasks_;
+    /// Set of disabled task nodes (by ID).
+    TaskIDSet disabled_tasks_;
 
-    //Set of Active Condition Nodes
-    std::set<SANet::CondID> active_conds_;
+    /// Set of active condition nodes (by ID).
+    CondIDSet active_conds_;
 
-    //Set of Active Task Nodes
-    std::set<SANet::CondID> disabled_conds_;
+    /// Set of disabled condition nodes (by ID).
+    CondIDSet disabled_conds_;
 
     /// Goals.
     GoalMap goals_;
@@ -439,26 +467,11 @@ namespace SANet {
     int step_;
 
 
-
-//    bool restrict_prop_to_clinks_;
-
-
-//    std::multimap<TaskID, SA_POP::CausalLink> causal_links_by_first_;
-//    std::multimap<CondID, SA_POP::CausalLink> causal_links_by_cond_;
-//    std::multimap<TaskID, SA_POP::CausalLink> causal_links_by_second_;
-
-
-
     // ************************************************************************
     // State helper methods.
     // ************************************************************************
 
     void reset_step();
-
-    //bool is_clink_first_to_cond_by_first(TaskID task, CondID cond);
-    //bool is_clink_first_to_cond_by_cond (CondID cond, TaskID task);
-    //bool is_clink_cond_to_second_by_second(TaskID task, CondID cond);
-    //bool is_clink_cond_to_second_by_cond(CondID cond, TaskiD second);
   };
 };
 
diff --git a/SA_POP/SANet/SANet_Standalone.mpc b/SA_POP/SANet/SANet_Standalone.mpc
index d49da025fcc..0f6a4c4b165 100644
--- a/SA_POP/SANet/SANet_Standalone.mpc
+++ b/SA_POP/SANet/SANet_Standalone.mpc
@@ -1,7 +1,8 @@
 project(SANet_Demo) : xerces, aceexe, sapop_xml {
   exename = SANet_Demo
 
-  includes += $(SAPOP_ROOT)
+  includes += $(SAPOP_ROOT) \
+              $(SAPOP_ROOT)/UserInput
 
   macros = SANET_STANDALONE
 
@@ -15,6 +16,9 @@ project(SANet_Demo) : xerces, aceexe, sapop_xml {
 
     SANet_XML_Typedefs.h
     SANetFileIn.h
+
+    $(SAPOP_ROOT)/UserInput/InputCL.h
+    $(SAPOP_ROOT)/UserInput/Question.h
   }
 
 
@@ -29,6 +33,8 @@ project(SANet_Demo) : xerces, aceexe, sapop_xml {
     SANet_XML_Typedefs.cpp
     SANetFileIn.cpp
     XML_SANet.cpp
+
+    $(SAPOP_ROOT)/UserInput/InputCL.cpp
   }
 
   Documentation_Files {
diff --git a/SA_POP/SANet/SANet_Types.h b/SA_POP/SANet/SANet_Types.h
index fa52d12647d..5b4483b516f 100644
--- a/SA_POP/SANet/SANet_Types.h
+++ b/SA_POP/SANet/SANet_Types.h
@@ -68,6 +68,9 @@ namespace SANet {
   /// Type of a probability.
   typedef SA_POP::Probability Probability;
 
+  /// Type of a conditional probability.
+  typedef SA_POP::ConditionalProb ConditionalProb;
+
   /// Type of a (precondition or effect) link weight.
   typedef SA_POP::LinkWeight LinkWeight;
 
@@ -248,6 +251,22 @@ namespace SANet {
   /// Type of a probability.
   typedef EUCalc Probability;
 
+  /// Type of a conditional probability.
+  struct ConditionalProb {
+    // Probability when conditioned variable is true.
+    Probability true_prob;
+    // Probability when conditioned variable is false.
+    Probability false_prob;
+    bool operator== (const ConditionalProb &s) const { return this->true_prob == s.true_prob && this->false_prob == s.false_prob; };
+    bool operator!= (const ConditionalProb &s) const { return !(*this == s); };
+    bool operator< (const ConditionalProb &s) const
+    {
+      if (this->true_prob == s.true_prob)
+        return this->false_prob < s.false_prob;
+      return this->true_prob < s.true_prob;
+    };
+  };
+
   /// Type of a (precondition or effect) link weight.
   typedef EUCalc LinkWeight;
 
diff --git a/SA_POP/SANet/SANet_UI.cpp b/SA_POP/SANet/SANet_UI.cpp
index aeddd1edb6d..ad18f08cab1 100644
--- a/SA_POP/SANet/SANet_UI.cpp
+++ b/SA_POP/SANet/SANet_UI.cpp
@@ -20,6 +20,19 @@
 #include <string>
 #include "SANet.h"
 #include "SANetFileIn.h"
+#include "InputCL.h"
+
+
+namespace SANet {
+  namespace Default {
+    const size_t SA_MAX_STEPS = 1000;
+  };  /* SANet::Default namespace */
+};  /* SANet namespace */
+
+// Forward declaration of testing functions.
+int test_clone (std::string filename);
+int test_user_interface (void);
+int test_net_gen (void);
 
 using namespace SANet;
 
@@ -33,46 +46,402 @@ using namespace SANet;
  */
 int main (int argc, char *argv[])
 {
-  std::cout << "Spreading Activation Network User Interface" << std::endl;
+  std::cout << "Spreading Activation Network User Interface" << std::endl << std::endl;
+
+  // To run a test, uncomment appropriate test function.
+//  return test_clone ("simple.san.xml");
+//  return test_net_gen ();
+//  return test_user_interface ();
+
+  UserInterface::InputCL user_input;
 
   // Get filename from user.
-  std::cout << "Network file: ";
   std::string filename = "";
-  std::cin >> filename;
+  UserInterface::Question file_ques ("Spreading activation network file:");
+  if (user_input.ask (file_ques))
+    filename = file_ques.get_answer ();
+
+  // Get flag for whether to output network configurations to files.
+  bool output_to_file = false;
 
   // Build network.
   SANetFileIn in;
   SANet::Network *net = in.build_net (filename);
 
-  // Print XML representation to output1.xml.
-  std::ofstream out_file ("output1.xml");
-  if (out_file == 0){
-    std::string msg = "Unable to open output1.xml for writing";
-    throw msg;
+  // Display initial configuration.
+  std::cout << "Initial network configuration:" << std::endl;
+  net->print (std::cout, true);
+
+  // Print XML representation to output_init.xml.
+  if (output_to_file) {
+    std::ofstream file_init ("output_init.xml");
+    if (file_init == 0){
+      std::string msg = "Unable to open output_init.xml for writing";
+      throw msg;
+    }
+    net->print_xml (file_init);
+    file_init.close ();
   }
-  net->print_xml (out_file);
-  out_file.close ();
 
-/*
-  net->add_cond (1111, "C1", 1, 1, 0, 0);
-  net->add_cond (1112, "C2", 1, 1, 0, 0);
+  // Get max steps from user.
+  size_t max_steps = SANet::Default::SA_MAX_STEPS;
+  UserInterface::QuestionInt steps_ques("Max steps to run (10000 step limit): ", 0, 10000);
+  if (user_input.ask (steps_ques))
+    max_steps = steps_ques.get_answer_int ();
+  
+
+  // Run spreading activation.
+  net->update (max_steps);
+
+  // Display final configuration.
+  std::cout << "Final network configuration:" << std::endl;
+  net->print (std::cout, true);
+
+  // Print XML representation to output_final.xml.
+  if (output_to_file) {
+    std::ofstream file_final ("output_final.xml");
+    if (file_final == 0){
+      std::string msg = "Unable to open output_final.xml for writing";
+      throw msg;
+    }
+    net->print_xml (file_final);
+    file_final.close ();
+  }
+
+  // Delete network.
+  delete net;
+
+  // Wait for user to end program.
+//  UserInterface::Question end_ques ("Enter any character to end program:");
+//  user_input.ask (end_ques);
+
+  return 0;
+};
+
+int test_clone (std::string filename, bool output_to_file = false)
+{
+  UserInterface::InputCL user_input;
+
+  // Build network.
+  SANetFileIn in;
+  SANet::Network *net = in.build_net (filename);
+
+  // Create initial network clone.
+  SANet::Network *net_dupe_init = new SANet::Network (*net);
+
+  // Display initial configurations.
+  std::cout << "Initial network configuration:" << std::endl;
+  net->print (std::cout, true);
+  std::cout << "Initial clone network configuration:" << std::endl;
+  net_dupe_init->print (std::cout, true);
+
+  // Print initial XML representation of networks.
+  if (output_to_file) {
+    // Print initial network XML representation.
+    std::ofstream file_init ("output_init.xml");
+    if (file_init == 0){
+      std::string msg = "Unable to open output_init.xml for writing";
+      throw msg;
+    }
+    net->print_xml (file_init);
+    file_init.close ();
+
+    // Print initial clone network XML representation.
+    std::ofstream file_dupe_init ("output_clone_init.xml");
+    if (file_dupe_init == 0){
+      std::string msg = "Unable to open output_clone_init.xml for writing";
+      throw msg;
+    }
+    net_dupe_init->print_xml (file_dupe_init);
+    file_dupe_init.close ();
+  }
+
+  // Get max steps from user.
+  size_t max_steps = SANet::Default::SA_MAX_STEPS;
+  UserInterface::QuestionInt steps_ques("Max steps to run (10000 step limit): ", 0, 10000);
+  if (user_input.ask (steps_ques))
+    max_steps = steps_ques.get_answer_int ();
+  
+  // Run spreading activation on original network.
+  net->update (max_steps);
+
+  // Clone updated network.
+  SANet::Network *net_dupe_final = new SANet::Network (*net);
+
+  // Display final configurations.
+  std::cout << "Final network configuration (ORIGINAL net) after spreading activation:" << std::endl;
+  net->print (std::cout, true);
+  std::cout << "Network configuration (CLONE of INITIAL net with no spreading activation performed):" << std::endl;
+  net_dupe_init->print (std::cout, true);
+  std::cout << "Network configuration (CLONE of FINAL net after spreading activation):" << std::endl;
+  net_dupe_final->print (std::cout, true);
+
+  // Print final XML representation of networks.
+  if (output_to_file) {
+    // Print network XML representation.
+    std::ofstream file_final ("output_final.xml");
+    if (file_final == 0){
+      std::string msg = "Unable to open output_final.xml for writing";
+      throw msg;
+    }
+    net->print_xml (file_final);
+    file_final.close ();
+
+    // Print clone network XML representation.
+    std::ofstream file_dupe_final ("output_clone_final.xml");
+    if (file_dupe_final == 0){
+      std::string msg = "Unable to open output_clone_final.xml for writing";
+      throw msg;
+    }
+    net_dupe_init->print_xml (file_dupe_final);
+    file_dupe_final.close ();
+
+    // Print second (after SA) clone network XML representation.
+    std::ofstream file_dupe2_final ("output_clone2_final.xml");
+    if (file_dupe2_final == 0){
+      std::string msg = "Unable to open output_clone2_final.xml for writing";
+      throw msg;
+    }
+    net_dupe_final->print_xml (file_dupe2_final);
+    file_dupe2_final.close ();
+  }
+
+
+  // Run spreading activation on clones.
+  net_dupe_init->update (max_steps);
+  net_dupe_final->update (max_steps);
+
+  // Display final configurations.
+  std::cout << "Final network configuration (CLONE of INITIAL net) after spreading activation:" << std::endl;
+  net_dupe_init->print (std::cout, true);
+  std::cout << "Final network configuration (CLONE of FINAL net) after additional spreading activation:" << std::endl;
+  net_dupe_final->print (std::cout, true);
+
+
+  // Delete networks.
+  delete net;
+  delete net_dupe_init;
+  delete net_dupe_final;
+
+  // Wait for user to end program.
+  UserInterface::Question end_ques ("Enter any character to end program:");
+  user_input.ask (end_ques);
+
+  return 0;
+};
+
+
+
+namespace UserInterface {
+  namespace Testing {
+    /// Type of an example enumerated type for user input.
+    enum RunKind {CONTINUE, STOP, EXIT, INVALID};
+  };  /* UserInterface::Testing namespace */
+};  /* UserInterface namespace */
+
+
+int test_user_interface (void)
+{
+  std::string answer = "999999";
+  int answer_int = 999999;
+  UserInterface::Testing::RunKind answer_val = UserInterface::Testing::INVALID;
+  std::string answer_val_str = "InVsTr";
+  bool answer_bool = false;
+
+  UserInterface::InputCL user_input;
+
+  UserInterface::Question ques ("Testing display info.");
+
+  user_input.info (ques);
+
+  ques.set_prompt ("Testing prompt (enter anything):");
+  user_input.ask (ques);
+  std::cout << "Your answer was \"" << ques.get_answer () << "\"" << std::endl;
+
+  answer = "999999";
+  answer_int = 999999;
+  UserInterface::QuestionInt ques_int ("Enter an integer between -100 and 5000:", -100, 5000);
+
+  user_input.ask (ques_int);
+  answer = ques_int.get_answer ();
+  answer_int = ques_int.get_answer_int ();
+  std::cout << "Your answer was \"" << answer << "\" which equals " << answer_int << "." << std::endl;
+
+
+
+
+  std::cout << "QuestionChoice<int> case insensitive" << std::endl;
+  UserInterface::QuestionChoice<int> ques_choice_int ("Enter (O)ne, (T)wo, or (F)our:", -1);
+  ques_choice_int.add_mapping ("O", 1);
+  ques_choice_int.add_mapping ("One", 1);
+  ques_choice_int.add_mapping ("T", 2);
+  ques_choice_int.add_mapping ("Two", 2);
+  ques_choice_int.add_mapping ("F", 4);
+  ques_choice_int.add_mapping ("Four", 4);
+
+  answer = "InV";
+  answer_val_str = "InVsTr";
+  answer_int = -2;
+
+  user_input.ask (ques_choice_int);
+  answer = ques_choice_int.get_answer ();
+  answer_int = ques_choice_int.get_answer_val ();
+  switch (answer_int)
+  {
+  case 1:
+    answer_val_str = "1 value";
+    break;
+  case 2:
+    answer_val_str = "2 value";
+    break;
+  case 4:
+    answer_val_str = "4 value";
+    break;
+  case -1:
+    answer_val_str = "INVALID value";
+    break;
+  default:
+    answer_val_str = "Unknown answer value";
+    break;
+  }
+  std::cout << "Your answer was \"" << answer << "\" which equals " << answer_val_str << "." << std::endl;
+
+
+
+
+  std::cout << "QuestionChoice case insensitive" << std::endl;
+  UserInterface::QuestionChoice<UserInterface::Testing::RunKind> ques_choice ("Enter (C)ontinue, (S)top, or (E)xit:", UserInterface::Testing::INVALID);
+  ques_choice.add_mapping ("C", UserInterface::Testing::CONTINUE);
+  ques_choice.add_mapping ("Continue", UserInterface::Testing::CONTINUE);
+  ques_choice.add_mapping ("S", UserInterface::Testing::STOP);
+  ques_choice.add_mapping ("Stop", UserInterface::Testing::STOP);
+  ques_choice.add_mapping ("E", UserInterface::Testing::EXIT);
+  ques_choice.add_mapping ("Exit", UserInterface::Testing::EXIT);
+
+  answer = "InV";
+  answer_val_str = "InVsTr";
+  answer_val = UserInterface::Testing::INVALID;
+
+  user_input.ask (ques_choice);
+  answer = ques_choice.get_answer ();
+  answer_val = ques_choice.get_answer_val ();
+  switch (answer_val)
+  {
+  case UserInterface::Testing::CONTINUE:
+    answer_val_str = "CONTINUE value";
+    break;
+  case UserInterface::Testing::STOP:
+    answer_val_str = "STOP value";
+    break;
+  case UserInterface::Testing::EXIT:
+    answer_val_str = "EXIT value";
+    break;
+  case UserInterface::Testing::INVALID:
+    answer_val_str = "INVALID value";
+    break;
+  default:
+    answer_val_str = "Unknown answer value";
+    break;
+  }
+  std::cout << "Your answer was \"" << answer << "\" which equals " << answer_val_str << "." << std::endl;
+
+
+  std::cout << "QuestionChoice case sensitive" << std::endl;
+  UserInterface::QuestionChoice<UserInterface::Testing::RunKind> ques_choice_case ("Enter (C)ontinue, (S)top, or (E)xit:", UserInterface::Testing::INVALID, true);
+  ques_choice_case.add_mapping ("C", UserInterface::Testing::CONTINUE);
+  ques_choice_case.add_mapping ("Continue", UserInterface::Testing::CONTINUE);
+  ques_choice_case.add_mapping ("S", UserInterface::Testing::STOP);
+  ques_choice_case.add_mapping ("Stop", UserInterface::Testing::STOP);
+  ques_choice_case.add_mapping ("E", UserInterface::Testing::EXIT);
+  ques_choice_case.add_mapping ("Exit", UserInterface::Testing::EXIT);
+
+  answer = "InV";
+  answer_val_str = "InVsTr";
+  answer_val = UserInterface::Testing::INVALID;
+
+  user_input.ask (ques_choice_case);
+  answer = ques_choice_case.get_answer ();
+  answer_val = ques_choice_case.get_answer_val ();
+  switch (answer_val)
+  {
+  case UserInterface::Testing::CONTINUE:
+    answer_val_str = "CONTINUE value";
+    break;
+  case UserInterface::Testing::STOP:
+    answer_val_str = "STOP value";
+    break;
+  case UserInterface::Testing::EXIT:
+    answer_val_str = "EXIT value";
+    break;
+  case UserInterface::Testing::INVALID:
+    answer_val_str = "INVALID value";
+    break;
+  default:
+    answer_val_str = "Unknown answer value";
+    break;
+  }
+  std::cout << "Your answer was \"" << answer << "\" which equals " << answer_val_str << "." << std::endl;
+
+
+  std::cout << "QuestionBool" << std::endl;
+  UserInterface::QuestionBool ques_bool ("Enter (Y)es or (N)o:", false);
+
+  answer = "InV";
+  answer_val_str = "InVsTr";
+  answer_bool = true;
+
+  user_input.ask (ques_bool);
+  answer = ques_bool.get_answer ();
+  answer_bool = ques_bool.get_answer_val ();
+  switch (answer_bool)
+  {
+  case true:
+    answer_val_str = "TRUE value";
+    break;
+  case false:
+    answer_val_str = "FALSE value";
+    break;
+  default:
+    answer_val_str = "Unknown answer value";
+    break;
+  }
+  std::cout << "Your answer was \"" << answer << "\" which equals " << answer_val_str << "." << std::endl;
+
+
+  // Wait for user to end program.
+  UserInterface::Question end_ques ("Enter any character to end program:");
+  user_input.ask (end_ques);
+
+  return 0;
+};
+
+
+
+int test_net_gen (void)
+{
+  UserInterface::InputCL user_input;
+
+  // Build network.
+  SANet::Network *net = new SANet::Network ();
+
+  net->add_cond (1111, "C1", 1, 1, 0, 0, ENVIRON);
+  net->add_cond (1112, "C2", 1, 1, 0, 0, ENVIRON);
   net->add_task (2221, "A1", 1, 0, 0.375);
-  net->add_cond (1113, "C3", 1, 0, 1, 10);
-  net->add_cond (1114, "C4", 1, 0, 1, 10);
+  net->add_cond (1113, "C3", 1, 0, 1, 10, ENVIRON);
+  net->add_cond (1114, "C4", 1, 0, 1, 10, ENVIRON);
   net->add_precond_link (1111, 2221, 0.75, 0);
   net->add_precond_link (1112, 2221, 0.5, 0.25);
   net->add_effect_link (2221, 1113, 1);
   net->add_effect_link (2221, 1114, 0.9);
-*/
 
 /*
-  net->add_cond (1110, "C0", 1, 1, 0, 0);
+  net->add_cond (1110, "C0", 1, 1, 0, 0, ENVIRON);
   net->add_task (2221, "A1", 1, 0, 0.5);
   net->add_task (2222, "A2", 1, 0, 0.5);
-  net->add_cond (1111, "C1", 1, 0, 1, 0);
-  net->add_cond (1112, "C2", 1, 0, 1, 0);
+  net->add_cond (1111, "C1", 1, 0, 1, 0, ENVIRON);
+  net->add_cond (1112, "C2", 1, 0, 1, 0, ENVIRON);
   net->add_task (2223, "A3", 1, 1, 0.25);
-  net->add_cond (1113, "C3", 1, 0, 1, 10);
+  net->add_cond (1113, "C3", 1, 0, 1, 10, ENVIRON);
   net->add_precond_link (1110, 2221, 1, 0);
   net->add_precond_link (1110, 2222, 1, 0);
   net->add_effect_link (2221, 1111, 1);
@@ -83,115 +452,58 @@ int main (int argc, char *argv[])
 */
 
 /*
-  net->add_cond (1111, "C1", 1, 1, 0, 0);
-  net->add_cond (1112, "C2", 1, 1, 0, 0);
+  net->add_cond (1111, "C1", 1, 1, 0, 0, ENVIRON);
+  net->add_cond (1112, "C2", 1, 1, 0, 0, ENVIRON);
   net->add_task (2221, "A1", 1, 1, 0.5);
   net->add_task (2222, "A2", 1, 3, 0.5);
-  net->add_cond (1113, "C3", 1, 0, 1, 10);
+  net->add_cond (1113, "C3", 1, 0, 1, 10, ENVIRON);
   net->add_precond_link (1111, 2221, 1, 0);
   net->add_precond_link (1112, 2222, 1, 0);
   net->add_effect_link (2221, 1113, 1);
   net->add_effect_link (2222, 1113, -1);
 */
 
-/*
-  net->print ();
-
-  net->update (10);
 
-  std::cout << std::endl;
+  // Display initial configuration.
+  std::cout << "Initial network configuration:" << std::endl;
   net->print (std::cout, true);
-*/
-
-/*
-  std::string filename = "";
-  Parser::XML_Parser parser;
-  Parser::XML_Object *obj;
-  Parser::SA_Net_Builder builder;
-  Network *net;
-
-  // Get network file from user.
-  std::cout << "Network file: ";
-  std::cin >> filename;
-  
-  try {
-    obj = parser.parse_file (filename);
-  } catch (Parser::Invalid_File e) {
-    std::cerr << "Invalid File exception occurred while opening network file." << std::endl;
-    std::cerr << e.err_msg ();
-    return -1;
-  } catch (Parser::Duplicate_Param e) {
-    std::cerr << "Duplicate Parameter exception occurred while parsing network file." << std::endl;
-    std::cerr << e.err_msg ();
-    return -1;
-  } catch (Parser::Invalid_Character e) {
-    std::cerr << "Invalid Character exception occurred while parsing network file." << std::endl;
-    std::cerr << e.err_msg ();
-    return -1;
-  } catch (Parser::Invalid_Param_Name e) {
-    std::cerr << "Invalid Parameter Name exception occurred while parsing network file." << std::endl;
-    std::cerr << e.err_msg ();
-    return -1;
-  } catch (Parser::Invalid_Param_Type e) {
-    std::cerr << "Invalid Parameter Type exception occurred while parsing network file." << std::endl;
-    std::cerr << e.err_msg ();
-    return -1;
-  } catch (Parser::Invalid_Tag_Name e) {
-    std::cerr << "Invalid Tag Name exception occurred while parsing network file." << std::endl;
-    std::cerr << e.err_msg ();
-    return -1;
-  } catch (char *e) {
-    std::cerr << "Exception occurred while parsing network file." << std::endl;
-    std::cerr << e;
-    return -1;
-  } catch (...) {
-    std::cerr << "Unknown exception occurred while parsing network file.";
-    std::cerr << std::endl;
-    return -1;
-  }
 
-  try {
-    net = builder.build_net (obj);
-  } catch (char *e) {
-    std::cerr << "Exception occurred while building network." << std::endl;
-    std::cerr << e;
-    return -1;
-  } catch (...) {
-    std::cerr << "Unknown exception occurred while building network.";
-    std::cerr << std::endl;
-    return -1;
+  // Print XML representation to output_init.xml.
+  std::ofstream file_init ("output_init.xml");
+  if (file_init == 0){
+    std::string msg = "Unable to open output_init.xml for writing";
+    throw msg;
   }
-*/
-  std::cout << "Initial network configuration:" << std::endl;
-  net->print ();
+  net->print_xml (file_init);
+  file_init.close ();
 
   // Get max steps from user.
-  std::cout << "Max steps to run: ";
-  std::string max_steps_str = "";
-  std::cin >> max_steps_str;
-
+  size_t max_steps = SANet::Default::SA_MAX_STEPS;
+  UserInterface::QuestionInt steps_ques("Max steps to run (10000 step limit): ", 0, 10000);
+  if (user_input.ask (steps_ques))
+    max_steps = steps_ques.get_answer_int ();
+  
   // Run spreading activation.
-  net->update (atoi (max_steps_str.c_str ()));
+  net->update (max_steps);
 
+  // Display final configuration.
   std::cout << "Final network configuration:" << std::endl;
   net->print (std::cout, true);
 
-  std::ofstream out2_file ("output2.xml");
-  if (out2_file == 0){
-    std::string msg = "Unable to open output2.xml for writing";
+  // Print XML representation to output_final.xml.
+  std::ofstream file_final ("output_final.xml");
+  if (file_final == 0){
+    std::string msg = "Unable to open output_final.xml for writing";
     throw msg;
   }
-  net->print_xml (out2_file);
-  out2_file.close ();
+  net->print_xml (file_final);
+  file_final.close ();
 
-//  delete obj;
   delete net;
 
-//****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP
-  std::cout << "Enter any character to end program: ";
-  char temp_;
-  std::cin>>temp_;
-//****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP
+  // Wait for user to end program.
+  UserInterface::Question end_ques ("Enter any character to end program:");
+  user_input.ask (end_ques);
 
   return 0;
-}
+};
diff --git a/SA_POP/SANet/SANode.cpp b/SA_POP/SANet/SANode.cpp
index 2a8838043a8..0eacee63dec 100644
--- a/SA_POP/SANet/SANode.cpp
+++ b/SA_POP/SANet/SANode.cpp
@@ -25,7 +25,7 @@ Node::Node (NodeID ID, std::string name, MultFactor atten_factor)
   step_ (0),
   prob_changed_ (false),
   util_changed_ (false) ,
-  active(true)
+  active_ (true)
 {
   // Initialize probability and utility info.
   pos_util_.utility = 0;
@@ -44,6 +44,50 @@ Node::Node (NodeID ID, std::string name, MultFactor atten_factor)
   post_links_.clear ();
 };
 
+// Copy constructor. Performs initialization by making a deep copy
+// of the provided node (with the exception of network structural
+// information about other nodes).
+// (WARNING: Links, including their probability values and node
+// pointers, to & from this node are EMPTY in the newly created copy.)
+Node::Node (const Node &s)
+: ID_ (s.ID_),
+  active_ (s.active_),
+  name_ (s.name_),
+  atten_factor_ (s.atten_factor_),
+  step_ (s.step_),
+  prob_changed_ (s.prob_changed_),
+  util_changed_ (s.util_changed_)
+{
+  // Initialize probability and utility info.
+  this->pos_util_ = s.pos_util_;
+  this->neg_util_ = s.neg_util_;
+  this->true_prob_ = s.true_prob_;
+  this->false_prob_ = s.false_prob_;
+
+  // Initialize (EMPTY) pre- and post-node maps & links.
+  this->pre_nodes_.clear ();
+  this->pre_links_.clear ();
+  this->post_nodes_.clear ();
+  this->post_links_.clear ();
+
+// Node data members.
+//    NodeID ID_;
+//    bool active_;
+//    std::string name_;
+//    MultFactor atten_factor_;
+//    int step_;
+//    NodeMap pre_nodes_;
+//    NodeMap post_nodes_;
+//    LinkMap pre_links_;
+//    LinkMap post_links_;
+//    bool prob_changed_;
+//    bool util_changed_;
+//    Utility_Info pos_util_;
+//    Utility_Info neg_util_;
+//    Probability_Info true_prob_;
+//    Probability_Info false_prob_;
+};
+
 Node::~Node ()
 {
   // Nothing to do.
@@ -93,7 +137,7 @@ std::string Node::get_name (void)
 /// Set activity flag
 void Node::set_activity (bool state)
 {
-  active = state;
+  this->active_ = state;
 }
 
 NodeID Node::get_ID (void)
@@ -120,10 +164,52 @@ const LinkMap& Node::get_post (void)
 TaskNode::TaskNode (NodeID ID, std::string name, MultFactor atten_factor,
                           TaskCost cost, Probability prior_prob)
 : Node (ID, name, atten_factor),
-  cost_ (cost),
-  prior_prob_ (prior_prob)
+  prior_prob_ (prior_prob),
+  cost_ (cost)
 {
-  // Nothing to do.
+  // Initialize (empty) pre-node maps (true/false conditional probabilities for preconditions).
+  this->pre_true_probs_.clear ();
+  this->pre_false_probs_.clear ();
+};
+
+// Copy constructor. Performs initialization by making a deep copy
+// of the provided node (with the exception of network structural
+// information about other nodes).
+// (WARNING: Links, including their probability values and node
+// pointers, to & from this node are EMPTY in the newly created copy.)
+TaskNode::TaskNode (const TaskNode &s)
+: Node (s),
+  prior_prob_ (s.prior_prob_),
+  cost_ (s.cost_)
+{
+  // Initialize (EMPTY) pre-node maps (true/false conditional probabilities for preconditions).
+  this->pre_true_probs_.clear ();
+  this->pre_false_probs_.clear ();
+
+  // All other data members initialized to copy values by base class.
+
+// Node data members.
+//    NodeID ID_;
+//    bool active_;
+//    std::string name_;
+//    MultFactor atten_factor_;
+//    int step_;
+//    NodeMap pre_nodes_;
+//    NodeMap post_nodes_;
+//    LinkMap pre_links_;
+//    LinkMap post_links_;
+//    bool prob_changed_;
+//    bool util_changed_;
+//    Utility_Info pos_util_;
+//    Utility_Info neg_util_;
+//    Probability_Info true_prob_;
+//    Probability_Info false_prob_;
+
+// TaskNode additional data members.
+//    Probability prior_prob_;
+//    TaskCost cost_;
+//    LinkMap pre_true_probs_;
+//    LinkMap pre_false_probs_;
 };
 
 TaskNode::~TaskNode (void)
@@ -145,7 +231,7 @@ bool TaskNode::update (void)
 {
 
   //Check to see if node is active before updating 
-  if(!active)
+  if(!(this->active_))
   {
     //the node should return as not changing the network
 	step_++;
@@ -734,6 +820,27 @@ void TaskNode::add_precond (CondID ID, CondNode *node, Probability true_prob,
   node->add_post_link (ID_, this, weight);
 };
 
+// Get conditional probability of success for a particular precondition.
+ConditionalProb TaskNode::get_precond_prob (CondID cond_ID)
+{
+  // Find conditional probability of success when precondition is true.
+  SANet::LinkMap::iterator link_true_iter = this->pre_true_probs_.find (cond_ID);
+  if (link_true_iter == this->pre_true_probs_.end ())
+    throw UnknownNode ();
+
+  // Find conditional probability of success when precondition is false.
+  SANet::LinkMap::iterator link_false_iter = this->pre_false_probs_.find (cond_ID);
+  if (link_false_iter == this->pre_false_probs_.end ())
+    throw UnknownNode ();
+
+  // Create conditional probability structure with true and false conditional probabilities.
+  ConditionalProb precond_prob;
+  precond_prob.true_prob = link_true_iter->second;
+  precond_prob.false_prob = link_false_iter->second;
+  
+  return precond_prob;
+};
+
 void TaskNode::add_effect (CondID ID, CondNode *node, LinkWeight weight)
 {
   // Add node to post-nodes.
@@ -769,6 +876,17 @@ void TaskNode::update_effect (CondID ID, CondNode *node, LinkWeight weight)
   node->update_pre_link (ID_, this, weight);
 };
 
+// Get probability of effect (link weight) for a particular effect condition.
+Probability TaskNode::get_effect_prob (CondID cond_ID)
+{
+  // Find probability of effect.
+  SANet::LinkMap::iterator link_iter = this->post_links_.find (cond_ID);
+  if (link_iter == this->post_links_.end ())
+    throw UnknownNode ();
+
+  return link_iter->second;
+};
+
 Probability TaskNode::get_prior (void)
 {
   return prior_prob_;
@@ -807,6 +925,46 @@ CondNode::CondNode (CondID ID, std::string name, MultFactor atten_factor,
   }
 };
 
+// Copy constructor. Performs initialization by making a deep copy
+// of the provided node (with the exception of network structural
+// information about other nodes).
+// (WARNING: Links, including their probability values and node
+// pointers, to & from this node are EMPTY in the newly created copy.)
+CondNode::CondNode (const CondNode &s)
+: Node (s),
+  goal_util_ (s.goal_util_),
+  init_true_prob_ (s.init_true_prob_),
+  true_prob_from_ (s.true_prob_from_),
+  false_prob_from_ (s.false_prob_from_),
+  cond_kind_ (s.cond_kind_)
+{
+  // All other data members initialized to copy values by base class.
+
+// Node data members.
+//    NodeID ID_;
+//    bool active_;
+//    std::string name_;
+//    MultFactor atten_factor_;
+//    int step_;
+//    NodeMap pre_nodes_;
+//    NodeMap post_nodes_;
+//    LinkMap pre_links_;
+//    LinkMap post_links_;
+//    bool prob_changed_;
+//    bool util_changed_;
+//    Utility_Info pos_util_;
+//    Utility_Info neg_util_;
+//    Probability_Info true_prob_;
+//    Probability_Info false_prob_;
+
+// CondNode additional data members.
+//    Utility goal_util_;
+//    Probability init_true_prob_;
+//    TaskID true_prob_from_;
+//    TaskID false_prob_from_;
+//    CondKind cond_kind_;
+};
+
 CondNode::~CondNode (void)
 {
   // Nothing to do.
@@ -1001,7 +1159,7 @@ bool CondNode::update (void)
 {
 
   //Check to see if node is active before updating 
-  if(!active)
+  if(!(this->active_))
   {
 	step_++;
     //the node should return as not changing the network
diff --git a/SA_POP/SANet/SANode.h b/SA_POP/SANet/SANode.h
index 4a205e86183..2a344adf09b 100644
--- a/SA_POP/SANet/SANode.h
+++ b/SA_POP/SANet/SANode.h
@@ -77,6 +77,16 @@ namespace SANet {
      */
     Node (NodeID ID, std::string name, MultFactor atten_factor);
 
+    /// Copy constructor. Performs initialization by making a deep copy
+    /// of the provided node (with the exception of network structural
+    /// information about other nodes).
+    /// (WARNING: Links, including their probability values and node
+    /// pointers, to & from this node are EMPTY in the newly created copy.)
+    /**
+     * @param s  Node to copy.
+     */
+    Node (const Node &s);
+
     /// Destructor.
     virtual ~Node ();
 
@@ -165,7 +175,7 @@ namespace SANet {
 	void reset_step();
 
 	bool is_active(){
-		return active;
+		return active_;
 	}
 
   protected:
@@ -173,7 +183,7 @@ namespace SANet {
     NodeID ID_;
 
     /// Flag indicating whether the node is active.
-    bool active;
+    bool active_;
 
     /// Name of node (descriptive only).
     std::string name_;
@@ -240,6 +250,16 @@ namespace SANet {
     TaskNode (TaskID ID, std::string name, MultFactor atten_factor, TaskCost cost,
       Probability prior_prob);
 
+    /// Copy constructor. Performs initialization by making a deep copy
+    /// of the provided node (with the exception of network structural
+    /// information about other nodes).
+    /// (WARNING: Links, including their probability values and node
+    /// pointers, to & from this node are EMPTY in the newly created copy.)
+    /**
+     * @param s  Task node to copy.
+     */
+    TaskNode (const TaskNode &s);
+
     /// Destructor.
     virtual ~TaskNode (void);
 
@@ -296,20 +316,15 @@ namespace SANet {
      */
     virtual Utility get_utility (int step);
 
-    /// Get Prior of the TaskNode.
+    /// Get prior probability of the task.
     /**
-     * 
-     *
-     * @return  Expected utility.
+     * @return  Prior probability of the task.
      */
     virtual Probability get_prior (void);
 
-    /// Update Prior of the TaskNode.
+    /// Update prior probability of the task.
     /**
-     * 
-     * @param prior the new prior for the task
-     *
-     * 
+     * @param prior  The new prior probability of the task.
      */
     virtual void update_prior (Probability prior);
 
@@ -329,11 +344,19 @@ namespace SANet {
     virtual void add_precond (CondID ID, CondNode *node, Probability true_prob,
       Probability false_prob);
 
+    /// Get conditional probability of success for a particular precondition.
+    /**
+     * @param cond_ID  Precondition node.
+     *
+     * @return  Conditional probability of the link.
+     */
+    virtual ConditionalProb get_precond_prob (CondID cond_ID);
+
     /// Add effect link.
     /**
-     * @param ID  Node ID.
+     * @param ID  ID of effect condition node ID.
      *
-     * @param node  Node pointer.
+     * @param node  Pointer to effect condition node.
      *
      * @param weight  Link weight (probability task sets condition to
      * true, or negative of the probability task sets condition to false).
@@ -342,7 +365,7 @@ namespace SANet {
 
     /// Update effect link.
     /**
-     * @param ID  Node ID.
+     * @param ID  ID of effect condition node ID.
      *
      * @param node  Node pointer.
      *
@@ -351,6 +374,14 @@ namespace SANet {
      */
     virtual void update_effect (CondID ID, CondNode *node, LinkWeight weight);
 
+    /// Get probability of effect (link weight) for a particular effect condition.
+    /**
+     * @param cond_ID  Effect condition node ID.
+     *
+     * @return  Conditional probability of the link.
+     */
+    virtual Probability get_effect_prob (CondID cond_ID);
+
 	void set_pos_util(double util);
 
 	Utility_Info get_pos_util();
@@ -397,6 +428,16 @@ namespace SANet {
     CondNode (CondID ID, std::string name, MultFactor atten_factor,
        Probability true_prob, Probability false_prob, Utility goal_util, CondKind cond_kind);
 
+    /// Copy constructor. Performs initialization by making a deep copy
+    /// of the provided node (with the exception of network structural
+    /// information about other nodes).
+    /// (WARNING: Links, including their probability values and node
+    /// pointers, to & from this node are EMPTY in the newly created copy.)
+    /**
+     * @param s  Condition node to copy.
+     */
+    CondNode (const CondNode &s);
+
     /// Destructor.
     virtual ~CondNode (void);
 
diff --git a/SA_POP/SA_POP_Types.h b/SA_POP/SA_POP_Types.h
index 5cf91c6b04d..ba17bf3feea 100644
--- a/SA_POP/SA_POP_Types.h
+++ b/SA_POP/SA_POP_Types.h
@@ -36,7 +36,7 @@
 #define SA_POP_DEBUG_VERBOSE 30
 
 // SET current SA-POP Debug output level.
-#define SA_POP_DEBUG_LEVEL SA_POP_DEBUG_QUIET
+#define SA_POP_DEBUG_LEVEL SA_POP_DEBUG_VERBOSE
 
 #define _CRTDBG_MAP_ALLOC
 #if defined (SA_POP_HAS_ACE)
@@ -124,6 +124,22 @@ namespace SA_POP {
   /// Type of a probability.
   typedef EUCalc Probability;
 
+  /// Type of a conditional probability.
+  struct ConditionalProb {
+    // Probability when conditioned variable is true.
+    Probability true_prob;
+    // Probability when conditioned variable is false.
+    Probability false_prob;
+    bool operator== (const ConditionalProb &s) const { return this->true_prob == s.true_prob && this->false_prob == s.false_prob; };
+    bool operator!= (const ConditionalProb &s) const { return !(*this == s); };
+    bool operator< (const ConditionalProb &s) const
+    {
+      if (this->true_prob == s.true_prob)
+        return this->false_prob < s.false_prob;
+      return this->true_prob < s.true_prob;
+    };
+  };
+
   /// Type of a (precondition or effect) link weight.
   typedef EUCalc LinkWeight;
 
diff --git a/SA_POP/Standalone/SAPOP_Demo.mpc b/SA_POP/Standalone/SAPOP_Demo.mpc
index ec49404f256..53194eeec62 100644
--- a/SA_POP/Standalone/SAPOP_Demo.mpc
+++ b/SA_POP/Standalone/SAPOP_Demo.mpc
@@ -1,16 +1,17 @@
 project(SA_POP_Demo) : xerces, aceexe, sapop_core_standalone {
   exename = SA_POP_Demo
 
-  Source_Files {
-    SA_POP_Demo.cpp
-    UserInput.cpp
-  }
+  includes += $(SAPOP_ROOT)/UserInput
 
-  Inline_Files {
+  Header_Files {
+    $(SAPOP_ROOT)/UserInput/InputCL.h
+    $(SAPOP_ROOT)/UserInput/Question.h
   }
 
-  Header_Files {
-    UserInput.h
+  Source_Files {
+    SA_POP_Demo.cpp
+
+    $(SAPOP_ROOT)/UserInput/InputCL.cpp
   }
 
   Documentation_Files {
diff --git a/SA_POP/Standalone/SA_POP_Demo.cpp b/SA_POP/Standalone/SA_POP_Demo.cpp
index b0f3e2d5f3e..64c916bef4f 100644
--- a/SA_POP/Standalone/SA_POP_Demo.cpp
+++ b/SA_POP/Standalone/SA_POP_Demo.cpp
@@ -14,49 +14,57 @@
 #include <iostream>
 #include "SA_POP_Types.h"
 #include "SA_Builder.h"
-#include "UserInput.h"
 #include "TaskMapFileIn.h"
 #include "SANet/SANetFileIn.h"
 #include "LogScreenOut.h"
 
+#include "InputCL.h"
+
+
+// SA-POP DEFAULTS.
+namespace SA_POP {
+  namespace Default {
+    const SA_POP::CondID CondIDMin = 1;
+    const SA_POP::CondID CondIDMax = 999999;
+    const SA_POP::Utility GoalUtilMin = -1000;
+    const SA_POP::Utility GoalUtilMax = 1000;
+  };  /* SA_POP::Default namespace */
+};  /* SA_POP namespace */
+
+// SPREADING ACTIVATION DEFAULTS.
+namespace SANet {
+  namespace Default {
+    const size_t SA_MAX_STEPS = 1000;
+  };  /* SANet::Default namespace */
+};  /* SANet namespace */
+
+
 
 int main (int argc, char* argv[])
 {
   SA_POP::SA_Builder builder;
   SANet::SANetFileIn sanet_in;
   SA_POP::TaskMapFileIn tm_in;
+  SA_POP::Planner *planner = 0;
+  UserInterface::InputCL user_input;
+
   std::string sanet_filename = "";
   std::string tm_filename = "";
+  SA_POP::CondID goal_id = 0;
+  SA_POP::Utility goal_util = 0;
+  size_t max_steps = SANet::Default::SA_MAX_STEPS;
 
-  // Get filenames from user.
-  std::cout << "Task Network file: ";
-//  sanet_filename = "../examples/output1.xml";
-//  sanet_filename = "../examples/SPACE.san.xml";
-//  sanet_filename = "../examples/test_graph1.san.xml";
-  std::cin >> sanet_filename;
-
-  std::cout << "Task Map file: ";
-//  tm_filename = "../examples/SPACE.tm.xml";
-//  tm_filename = "../examples/test_graph.tm.xml";
-  std::cin >> tm_filename;
 
-  SA_POP::Goal goal;
-  goal.goal_id = "UserSpecifiedGoal ID";
-  goal.name = "User specified goal";
-  goal.abs_times.clear ();
-  goal.rel_times.clear ();
-  goal.goal_conds.clear ();
-  goal.start_window = std::make_pair (0, 0);
+  // Get filenames from user.
+  UserInterface::Question sanet_file_ques ("Task Network file:");
+  if (user_input.ask (sanet_file_ques))
+    sanet_filename = sanet_file_ques.get_answer ();
+  UserInterface::Question tm_file_ques ("Task Map file:");
+  if (user_input.ask (tm_file_ques))
+    tm_filename = tm_file_ques.get_answer ();
 
-  // Get goal.
-  SA_POP::CondID goal_id;
-  SA_POP::Utility goal_util;
-  std::cout << "Goal condition ID: ";
-  std::cin >> goal_id;
-  std::cout << "Goal utility: ";
-  std::cin >> goal_util;
-  goal.goal_conds.insert (std::make_pair (goal_id, goal_util));
   
+  // Build task network and task map.
   try {
     sanet_in.build_net (sanet_filename, &builder);
     tm_in.build_task_map (tm_filename, &builder);
@@ -65,19 +73,45 @@ int main (int argc, char* argv[])
     std::cerr << std::endl;
     std::cerr << e;
   } catch (...) {
-    std::cerr << "UNKNOWN ERROR while planning." << std::endl;
+    std::cerr << "UNKNOWN ERROR while building task network and task map from files." << std::endl;
   }
 
 
-  SA_POP::Planner *planner = 0;
 
+  // Create goal.
+  SA_POP::Goal goal;
+  goal.goal_id = "UserSpecifiedGoal ID";
+  goal.name = "User specified goal";
+  goal.abs_times.clear ();
+  goal.rel_times.clear ();
+  goal.goal_conds.clear ();
+  goal.start_window = std::make_pair (0, 0);
+
+  // Get goal condition and utility from user.
+  UserInterface::QuestionInt goal_id_ques ("Goal condition ID:", SA_POP::Default::CondIDMin, SA_POP::Default::CondIDMax);
+  if (user_input.ask (goal_id_ques))
+    goal_id = goal_id_ques.get_answer_int ();
+  UserInterface::QuestionInt goal_util_ques ("Goal utility:", SA_POP::Default::GoalUtilMin, SA_POP::Default::GoalUtilMax);
+  if (user_input.ask (goal_util_ques))
+    goal_util = goal_util_ques.get_answer_int ();
+
+  goal.goal_conds.insert (std::make_pair (goal_id, goal_util));
+
+
+  // Get maximum steps of spreading activation from user.
+  UserInterface::QuestionInt steps_ques("Max steps to run (10000 step limit): ", 0, 10000);
+  if (user_input.ask (steps_ques))
+    max_steps = steps_ques.get_answer_int ();
+
+  
+  // Run SA-POP.
   try {
     planner = builder.get_planner ();
 
     SA_POP::LogScreenOut screen_out (std::cout);
     planner->add_out_adapter (&screen_out);
 
-    planner->plan (100, goal);
+    planner->plan (max_steps, goal);
   } catch (std::string e) {
     std::cerr << "ERROR while planning:" << std::endl;
     std::cerr << e;
@@ -89,11 +123,9 @@ int main (int argc, char* argv[])
 
   delete planner;
 
-//****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP
-  std::cout << "Enter any character to end program: ";
-  char temp_;
-  std::cin>>temp_;
-//****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP
+  // Wait for user to end program.
+//  UserInterface::Question end_ques ("Enter any character to end program:");
+//  user_input.ask (end_ques);
 
   return 0;
 }
diff --git a/SA_POP/Standalone/UserInput.cpp b/SA_POP/Standalone/UserInput.cpp
deleted file mode 100644
index a216b91cbff..00000000000
--- a/SA_POP/Standalone/UserInput.cpp
+++ /dev/null
@@ -1,33 +0,0 @@
-// -*- C++ -*-
-// $Id$
-
-//=============================================================================
-/**
- * @file  UserInput.cpp
- *
- * This file contains the UserInput class implementation for the input adapter
- * that provides a user interface for testing SA-POP.
- *
- * @author  John S. Kinnebrew <john.s.kinnebrew@vanderbilt.edu>
- */
-//=============================================================================
-
-#include "SA_POP_Types.h"
-#include "UserInput.h"
-#include "Builder.h"
-#include "Planner.h"
-
-
-using namespace SA_POP;
-
-// Constructor.
-UserInput::UserInput (void)
-{
-  //****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP
-};
-
-// Destructor.
-UserInput::~UserInput (void)
-{
-  //****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP****TEMP
-};
diff --git a/SA_POP/Standalone/UserInput.h b/SA_POP/Standalone/UserInput.h
deleted file mode 100644
index b1b2b52111c..00000000000
--- a/SA_POP/Standalone/UserInput.h
+++ /dev/null
@@ -1,42 +0,0 @@
-// -*- C++ -*-
-// $Id$
-
-//=============================================================================
-/**
- * @file  UserInput.h
- *
- * This file contains the UserInput class definition for the input adapter
- * that provides a user interface for testing SA-POP.
- *
- * @author  John S. Kinnebrew <john.s.kinnebrew@vanderbilt.edu>
- */
-//=============================================================================
-
-#ifndef SA_POP_USER_INPUT_H_
-#define SA_POP_USER_INPUT_H_
-
-#include "SA_POP_Types.h"
-#include "UserInput.h"
-#include "Builder.h"
-#include "Planner.h"
-
-
-namespace SA_POP {
-
-  /**
-   * @class UserInput
-   *
-   * @brief Input adapter that provides a user interface for testing SA-POP.
-   */
-  class UserInput {
-  public:
-    /// Constructor.
-    UserInput (void);
-
-    /// Destructor.
-    virtual ~UserInput (void);
-  };
-
-};  /* SA_POP namespace */
-
-#endif /* SA_POP_USER_INPUT_H_ */
diff --git a/SA_POP/UserInput/InputCL.cpp b/SA_POP/UserInput/InputCL.cpp
new file mode 100644
index 00000000000..b097a6d96b7
--- /dev/null
+++ b/SA_POP/UserInput/InputCL.cpp
@@ -0,0 +1,152 @@
+// -*- C++ -*-
+// $Id$
+
+//=============================================================================
+/**
+ * @file  InputCL.cpp
+ *
+ * This file contains the InputCL class implementation for the command line
+ * input adapter (helper class for command line interfaces).
+ *
+ * @author  John S. Kinnebrew <john.s.kinnebrew@vanderbilt.edu>
+ */
+//=============================================================================
+
+#include <iostream>
+#include <string>
+
+#include "InputCL.h"
+#include "Question.h"
+
+using namespace UserInterface;
+
+// Constructor.
+InputCL::InputCL (std::basic_ostream<char, std::char_traits<char> >& ostrm,
+                  std::basic_istream<char, std::char_traits<char> >& istrm)
+: ostrm_ (ostrm),
+  istrm_ (istrm)
+{
+  // Nothing to initialize.
+};
+
+// Destructor.
+InputCL::~InputCL (void)
+{
+  // Nothing to do.
+};
+
+// Provide info to user.
+void InputCL::info (UserInterface::Question info)
+{
+  this->ostrm_ << info.get_prompt ();
+  this->ostrm_ << std::endl;
+};
+
+// Ask the user a question (continues asking until they provide a valid answer).
+bool InputCL::ask (UserInterface::Question& question, size_t max_repeat)
+{
+  // Display question and get answer until receiving a valid response or maximum
+  // number of repeats has been reached.
+  std::string answer = "";
+  for (size_t reps = 0; reps < max_repeat; reps++) {
+    // Display question.
+    this->ostrm_ << question.get_prompt ();
+    this->ostrm_ << "  ";
+
+    // Get answer.
+    this->istrm_ >> answer;
+
+    // Break out of question asking loop if user provided a valid answer.
+    if (question.is_valid_answer (answer))
+      break;
+
+    // User provided an invalid answer, so display response.
+    this->ostrm_ << question.get_invalid_response ();
+    this->ostrm_ << std::endl;
+  }
+
+  // Set answer in question object and return flag indicating its validity.
+  return question.answer (answer);
+};
+
+
+
+
+
+
+
+// Constructor.
+QuestionInt::QuestionInt (std::string prompt, int min, int max, std::string invalid_response)
+: Question (prompt, invalid_response),
+  min_ (min),
+  max_ (max)
+{
+  // Nothing to do.
+};
+
+// Destructor.
+QuestionInt::~QuestionInt (void)
+{
+  // Nothing to do.
+};
+
+// Is an answer valid for this question?
+bool QuestionInt::is_valid_answer (std::string answer)
+{
+  int i;
+  std::istringstream answer_ss (answer);
+
+  if (answer_ss >> i)
+  { 
+    if (i >= this->min_ && i <= this->max_)
+      return true;
+  }
+  
+  return false;
+};
+
+// Get answer.
+int QuestionInt::get_answer_int ()
+{
+  int i = 0;
+  std::istringstream answer_ss (this->answer_);
+  
+  if (answer_ss >> i)
+    return i;
+  
+  return this->min_;
+};
+
+
+
+
+
+// Constructor
+QuestionBool::QuestionBool (std::string prompt, bool def_val, std::string invalid_response)
+: QuestionChoice (prompt, def_val, false, invalid_response)
+{
+  this->init_map ();
+};
+
+// Destructor.
+QuestionBool::~QuestionBool (void)
+{
+  // Nothing to do.
+};
+
+// Get answer.
+bool QuestionBool::get_answer_bool (void)
+{
+  return this->get_answer_val ();
+};
+
+// Initialize mapping with yes/no answers.
+void QuestionBool::init_map (void)
+{
+  this->answer_map_.clear ();
+  this->add_mapping ("Y", true);
+  this->add_mapping ("Yes", true);
+  this->add_mapping ("N", false);
+  this->add_mapping ("No", false);
+};
+
diff --git a/SA_POP/UserInput/InputCL.h b/SA_POP/UserInput/InputCL.h
new file mode 100644
index 00000000000..2656c967b6d
--- /dev/null
+++ b/SA_POP/UserInput/InputCL.h
@@ -0,0 +1,166 @@
+// -*- C++ -*-
+// $Id$
+
+//=============================================================================
+/**
+ * @file  InputCL.h
+ *
+ * This file contains the class definition of InputCL and related classes for
+ * the command line input adapter (helper class for command line interfaces).
+ *
+ * @author  John S. Kinnebrew <john.s.kinnebrew@vanderbilt.edu>
+ */
+//=============================================================================
+
+#ifndef USER_INTERFACE_INPUT_CL_H_
+#define USER_INTERFACE_INPUT_CL_H_
+
+#include <iostream>
+#include <string>
+
+#include "Question.h"
+
+namespace UserInterface {
+
+  namespace Default {
+    const size_t MAX_QUESTION_REPEAT = 5;
+ };  /* Default namespace */
+
+
+  /**
+   * @class InputCL
+   *
+   * @brief Command line input adapter (helper class for command line interfaces).
+   */
+  class InputCL {
+  public:
+    /// Constructor.
+    /**
+     * @param ostrm  Output stream to display questions/prompts and info to user.
+     *
+     * @param istrm  Input stream to get user input.
+     */
+    InputCL (std::basic_ostream<char, std::char_traits<char> >& ostrm
+      = std::cout, std::basic_istream<char, std::char_traits<char> >& istrm
+      = std::cin);
+
+    /// Destructor.
+    virtual ~InputCL (void);
+
+    /// Provide info to user.
+    /**
+     * @param info  Question class with info for user.
+     */
+    void info (UserInterface::Question info);
+
+    /// Ask the user a question.
+    /**
+     * @param question  Question for user (question object will be updated with last user answer upon return).
+     *
+     * @param max_repeat  Maximum number of times to repeat question when user provides invalid answer(s).
+     *
+     * @return  True if user provided a valid answer to question, false otherwise.
+     */
+    bool ask (UserInterface::Question& question, size_t max_repeat = UserInterface::Default::MAX_QUESTION_REPEAT);
+
+  protected:
+    /// Output stream to display questions/prompts and info to user.
+    std::basic_ostream<char, std::char_traits<char> >& ostrm_;
+
+    /// Input stream to get user input.
+    std::basic_istream<char, std::char_traits<char> >& istrm_;
+  };
+
+
+
+
+
+
+
+
+
+
+
+
+
+  /**
+   * @class QuestionInt
+   *
+   * @brief Class for a user question with an integer answer.
+   */
+  class QuestionInt : public Question  {
+  public:
+    /// Constructor.
+    /**
+     * @param prompt  Prompt/question for user.
+     *
+     * @param min  Minimum (inclusive) valid answer.
+     *
+     * @param max  Maximum (inclusive) valid answer.
+     *
+     * @param invalid_response  Response string for when user provides an invalid answer.
+     */
+    QuestionInt (std::string prompt, int min, int max, std::string invalid_response = UserInterface::Default::INVALID_RESPONSE_STR);
+
+    /// Destructor.
+    virtual ~QuestionInt (void);
+
+    /// Is an answer valid for this question?
+    /**
+     * @param answer  Answer to check validity.
+     *
+     * @return  True for a valid answer or false for an invalid answer.
+     */
+    virtual bool is_valid_answer (std::string answer);
+
+    /// Get answer.
+    /**
+     * @return  Answer from user (if no valid answer provided, returns minimum valid answer).
+     */
+    int get_answer_int (void);
+
+  protected:
+    /// Minimum (inclusive) valid answer.
+    int min_;
+
+    /// Maximum (inclusive) valid answer.
+    int max_;
+
+  };
+
+  /**
+   * @class QuestionBool
+   *
+   * @brief Class for a user question with a boolean (yes/no) answer.
+   *        Valid answer strings (case insensitive) corresponding to true are "y" and "yes".
+   *        Valid answer strings (case insensitive) corresponding to false are "n" and "no".
+   */
+  class QuestionBool : public QuestionChoice<bool>  {
+  public:
+    /// Constructor.
+    /**
+     * @param prompt  Prompt/question (or info) for user.
+     *
+     * @param def_val  Default value returned if no valid answer provided.
+     *
+     * @param invalid_response  Response string for when user provides an invalid answer.
+     */
+    QuestionBool (std::string prompt, bool def_val, std::string invalid_response = UserInterface::Default::INVALID_RESPONSE_STR);
+
+    /// Destructor.
+    virtual ~QuestionBool (void);
+
+    /// Get answer.
+    /**
+     * @return  Answer from user (if no valid answer provided, returns default value).
+     */
+    bool get_answer_bool (void);
+
+  protected:
+    /// Initialize mapping with yes/no answers.
+    void init_map (void);
+  };
+
+};  /* UserInterface namespace */
+
+#endif /* USER_INTERFACE_INPUT_CL_H_ */
diff --git a/SA_POP/UserInput/Question.cpp b/SA_POP/UserInput/Question.cpp
new file mode 100644
index 00000000000..14ffb39905d
--- /dev/null
+++ b/SA_POP/UserInput/Question.cpp
@@ -0,0 +1,124 @@
+// -*- C++ -*-
+// $Id$
+
+//=============================================================================
+/**
+ * @file  Question.cpp
+ *
+ * This file contains the implementation of Question classes for use with
+ * the command line input adapter (InputCL).
+ *
+ * @author  John S. Kinnebrew <john.s.kinnebrew@vanderbilt.edu>
+ */
+//=============================================================================
+
+#ifndef USER_INTERFACE_QUESTION_CPP_
+#define USER_INTERFACE_QUESTION_CPP_
+
+#include <string>
+#include <sstream>
+#include <map>
+#include <algorithm>
+
+#include "Question.h"
+
+using namespace UserInterface;
+
+
+
+// Constructor.
+template <typename T> 
+QuestionChoice<T>::QuestionChoice (std::string prompt, T invalid_val, bool match_case, std::string invalid_response)
+: Question (prompt, invalid_response),
+  invalid_val_ (invalid_val),
+  match_case_ (match_case)
+{
+  // Clear map from answers to values.
+  this->answer_map_.clear ();
+};
+
+// Destructor.
+template <typename T> 
+QuestionChoice<T>::~QuestionChoice (void)
+{
+  // Nothing to do.
+};
+
+// Is an answer valid for this question?
+template <typename T> bool
+QuestionChoice<T>::is_valid_answer (std::string answer)
+{
+  std::string ans = answer;
+
+  // If case insensitive, convert answer to upper case before checking answer map.
+  if (!this->match_case_)
+    std::transform(ans.begin(), ans.end(), ans.begin(), ::toupper);
+
+  // If answer is not in answer map, it is not valid.
+  if (this->answer_map_.find (ans) == this->answer_map_.end ())
+    return false;
+
+  return true;
+};
+
+// Get answer.
+template <typename T> T
+QuestionChoice<T>::get_answer_val (void)
+{
+  std::string ans = this->answer_;
+
+  // If case insensitive, convert answer to upper case before checking answer map.
+  if (!this->match_case_)
+    std::transform(ans.begin(), ans.end(), ans.begin(), ::toupper);
+
+  // Find answer in answer map.
+  std::map<std::string, T>::iterator answer_iter = this->answer_map_.find (ans);
+
+  // If answer is not in answer map, return invalid value.
+  if (answer_iter == this->answer_map_.end ())
+    return this->invalid_val_;
+
+  return answer_iter->second;
+};
+
+// Set complete mapping from answers to values.
+// (WARNING:  Map will completely replace all existing mappings.)
+template <typename T> void
+QuestionChoice<T>::set_map (const std::map<std::string, T> &answer_map)
+{
+  // Overwrite current mapping with new mapping (converting answers
+  // to upper case, if not case sensitive).
+  if (this->match_case_) {
+    this->answer_map_ = answer_map;
+  } else {
+    // Clear current map.
+    this->answer_map_.clear ();
+
+    // Convert each answer to upper case and insert with value into answer map.
+    std::string ans = "";
+    for (std::map<std::string, T>::const_iterator ans_iter = answer_map.begin (); ans_iter != answer_map; ans_iter++) {
+      ans = ans_iter->first;
+      std::transform(ans.begin(), ans.end(), ans.begin(), ::toupper);
+      this->answer_map_.insert (std::make_pair (ans, ans_iter->second));
+    }
+  }
+};
+
+// Add a mapping from an answer to a value (or replace with provided
+// value if a mapping already exists for the answer).
+template <typename T> void
+QuestionChoice<T>::add_mapping (std::string answer, T value)
+{
+  std::string ans = answer;
+
+  // If case insensitive, convert answer to upper case before inserting in answer map.
+  if (!this->match_case_)
+    std::transform(ans.begin(), ans.end(), ans.begin(), ::toupper);
+
+  this->answer_map_.insert (std::make_pair (ans, value));
+};
+
+
+
+
+#endif /* USER_INTERFACE_QUESTION_CPP_ */
diff --git a/SA_POP/UserInput/Question.h b/SA_POP/UserInput/Question.h
new file mode 100644
index 00000000000..05e841cb83c
--- /dev/null
+++ b/SA_POP/UserInput/Question.h
@@ -0,0 +1,172 @@
+// -*- C++ -*-
+// $Id$
+
+//=============================================================================
+/**
+ * @file  Question.h
+ *
+ * This file contains the declarations of Question classes for use with
+ * the command line input adapter (InputCL).
+ *
+ * @author  John S. Kinnebrew <john.s.kinnebrew@vanderbilt.edu>
+ */
+//=============================================================================
+
+#ifndef USER_INTERFACE_QUESTION_H_
+#define USER_INTERFACE_QUESTION_H_
+
+#include <string>
+#include <sstream>
+#include <map>
+
+namespace UserInterface {
+
+  namespace Default {
+    const std::string INVALID_RESPONSE_STR = "Sorry, that is not a valid answer.";
+  };  /* Default namespace */
+
+  /**
+   * @class Question
+   *
+   * @brief Base class for a user question (or info for user).
+   */
+  class Question {
+  public:
+    /// Constructor.
+    /**
+     * @param prompt  Prompt/question (or info) for user.
+     *
+     * @param invalid_response  Response string for when user provides an invalid answer.
+     */
+    Question (std::string prompt, std::string invalid_response = UserInterface::Default::INVALID_RESPONSE_STR)
+      : prompt_ (prompt), invalid_response_ (invalid_response), answer_ ("") { };
+
+    /// Destructor.
+    virtual ~Question (void) { };
+
+    /// Set prompt.
+    /**
+     * @param prompt  Prompt/question (or info) for user.
+     */
+    void set_prompt (std::string prompt) { this->prompt_ = prompt; };
+
+    /// Get prompt.
+    /**
+     * @return  Prompt/question (or info) for user.
+     */
+    std::string get_prompt () { return this->prompt_; };
+
+    /// Get response string for when user provides an invalid answer.
+    /**
+     * @return  Response string for when user provides an invalid answer.
+     */
+    std::string get_invalid_response () { return this->invalid_response_; };
+
+    /// Is an answer valid for this question?
+    /**
+     * @param answer  Answer to check validity.
+     *
+     * @return  True for a valid answer or false for an invalid answer.
+     */
+    virtual bool is_valid_answer (std::string answer) { return true; };
+
+    /// Provide user answer.
+    /**
+     * @param answer  User answer.
+     *
+     * @return  True for a valid answer or false for an invalid answer.
+     */
+    virtual bool answer (std::string answer) { if (this->is_valid_answer (answer)) {this->answer_ = answer; return true;} return false; };
+
+    /// Get answer.
+    /**
+     * @return  Answer from user (if no valid answer provided, returns empty string).
+     */
+    std::string get_answer () { return this->answer_; };
+
+  protected:
+    /// Prompt/question (or info) for user.
+    std::string prompt_;
+
+    /// Response to user when they provide an invalid answer to the question.
+    std::string invalid_response_;
+
+    /// Answer.
+    std::string answer_;
+  };
+  
+
+  /**
+   * @class QuestionChoice
+   *
+   * @brief Class for a user question with a mapping from answers to values.
+   */
+  template <typename T>
+  class QuestionChoice : public Question  {
+  public:
+    /// Class trait of its answer value type.
+    typedef T TYPE;
+
+    /// Constructor.
+    /**
+     * @param prompt  Prompt/question for user.
+     *
+     * @param invalid_val  Value to return if no valid answer provided.
+     *
+     * @param match_case  Match case of answer strings? (i.e., case sensitive?)
+     *
+     * @param invalid_response  Response string for when user provides an invalid answer.
+     */
+    QuestionChoice (std::string prompt, T invalid_val, bool match_case = false, std::string invalid_response = UserInterface::Default::INVALID_RESPONSE_STR);
+
+    /// Destructor.
+    virtual ~QuestionChoice (void);
+
+    /// Is an answer valid for this question?
+    /**
+     * @param answer  Answer to check validity.
+     *
+     * @return  True for a valid answer or false for an invalid answer.
+     */
+    virtual bool is_valid_answer (std::string answer);
+
+    /// Get answer.
+    /**
+     * @return  Value corresponding to answer from user (if no valid answer provided, returns invalid_val parameter from constructor).
+     */
+    T get_answer_val (void);
+
+    /// Set complete mapping from answers to values.
+    /// (WARNING:  Map will completely replace all existing mappings.)
+    /**
+     * @param answer_map  Map from valid answer strings to corresponding values.
+     */
+    void set_map (const std::map<std::string, T> &answer_map);
+
+    /// Add a mapping from an answer to a value (or replace with provided
+    /// value if a mapping already exists for the answer).
+    /**
+     * @param answer  Valid answer string.
+     *
+     * @param value  Value corresponding to answer string.
+     */
+    void add_mapping (std::string answer, T value);
+
+  protected:
+    /// Match case of strings? (i.e., case sensitive?)
+    bool match_case_;
+
+    /// Value to indicate invalid answer.
+    T invalid_val_;
+
+    /// Map from answers to values.
+    std::map<std::string, T> answer_map_;
+  };
+
+
+
+};  /* UserInterface namespace */
+
+#include "Question.cpp"
+
+#endif /* USER_INTERFACE_QUESTION_H_ */