TYPE SIGNATURES
  foo :: forall {a} {b}. (C a b, Num b) => a -> ()
  op :: forall a b. C a b => a -> b -> ()
TYPE CONSTRUCTORS
  class C{2} :: * -> * -> Constraint
COERCION AXIOMS
  axiom Bug.N:C :: forall a b. C a b = a -> b -> ()
Dependent modules: []
Dependent packages: [base-4.17.0.0]

==================== Typechecker ====================
Bug.$tcC
  = GHC.Types.TyCon
      12754692886077552850##64 18375870125396612007##64 Bug.$trModule
      (GHC.Types.TrNameS "C"#) 0# $krep
Bug.$tc'C:C
  = GHC.Types.TyCon
      302756782745842909##64 14248103394115774781##64 Bug.$trModule
      (GHC.Types.TrNameS "'C:C"#) 2# $krep
$krep [InlPrag=[~]] = GHC.Types.KindRepVar 0
$krep [InlPrag=[~]] = GHC.Types.KindRepVar 1
$krep [InlPrag=[~]] = GHC.Types.KindRepFun $krep $krep
$krep [InlPrag=[~]] = GHC.Types.KindRepFun $krep $krep
$krep [InlPrag=[~]] = GHC.Types.KindRepFun $krep $krep
$krep [InlPrag=[~]] = GHC.Types.KindRepFun GHC.Types.krep$* $krep
$krep [InlPrag=[~]] = GHC.Types.KindRepFun GHC.Types.krep$* $krep
$krep [InlPrag=[~]]
  = GHC.Types.KindRepTyConApp
      GHC.Types.$tcConstraint [] @GHC.Types.KindRep
$krep [InlPrag=[~]]
  = GHC.Types.KindRepTyConApp GHC.Tuple.$tc() [] @GHC.Types.KindRep
$krep [InlPrag=[~]]
  = GHC.Types.KindRepTyConApp
      Bug.$tcC
      ((:) @GHC.Types.KindRep
         $krep ((:) @GHC.Types.KindRep $krep [] @GHC.Types.KindRep))
Bug.$trModule
  = GHC.Types.Module
      (GHC.Types.TrNameS "main"#) (GHC.Types.TrNameS "Bug"#)
AbsBinds [a, b] [$dC, $dNum]
  {Exports: [foo <= foo
               wrap: <>]
   Exported types: foo :: forall {a} {b}. (C a b, Num b) => a -> ()
                   [LclId]
   Binds: foo x = op @a @b $dC x 3
   Evidence: [EvBinds{[W] $dC = $dC
                      [W] $dNum = $dNum}]}