1 files changed, 19 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_compile/tc109.hs b/testsuite/tests/typecheck/should_compile/tc109.hs
new file mode 100644
index 0000000000..0d9fdc051c
--- /dev/null
+++ b/testsuite/tests/typecheck/should_compile/tc109.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies,
+             UndecidableInstances #-}
+-- UndecidableInstances because 'b' appears in the context but not the head
+
+module ShouldCompile where
+
+-- This accepted by Hugs, but not by GHC 4.08.1
+-- Reported by Thomas Hallgren Nov 00
+
+class P a
+class R a b | b->a
+
+instance (P a,R a b) => P [b]
+
+{- GHC 4.08.1 doesn't seem to allow variables in the context that
+don't appear after the =>, but which are still ok since they are
+determined by the functional dependenices.  -}
+
+