[project @ 2000-10-16 15:16:02 by sewardj]

Make compile.

diff --git a/ghc/compiler/typecheck/TcUnify.lhs b/ghc/compiler/typecheck/TcUnify.lhs
index a026827..bc6f537 100644 (file)
--- a/ghc/compiler/typecheck/TcUnify.lhs
+++ b/ghc/compiler/typecheck/TcUnify.lhs
@@ -25,12 +25,12 @@ import Type ( funTyCon, Kind, unboxedTypeKind, boxedTypeKind, openTypeKind,
                  tidyOpenType, tidyOpenTypes, tidyTyVar
                )
 import TyCon   ( TyCon, isTupleTyCon, tupleTyConBoxity, tyConArity )
-import Name    ( hasBetterProv )
 import Var     ( TyVar, tyVarKind, varName, isSigTyVar )
 import VarSet  ( varSetElems )
 import TcType  ( TcType, TcTauType, TcTyVar, TcKind, newBoxityVar,
                  newTyVarTy, newTyVarTys, tcGetTyVar, tcPutTyVar, zonkTcType
                )
+import Name    ( isSystemName )
 
 -- others:
 import BasicTypes ( Arity, Boxity, isBoxed )
@@ -316,7 +316,7 @@ uUnboundVar swapped tv1 maybe_ty1 ps_ty2 ty2@(TyVarTy tv2)
                                -- Don't unify a signature type variable if poss
                        || k2 == openTypeKind
                                -- Try to get rid of open type variables as soon as poss
-                       || varName tv1 `hasBetterProv` varName tv2 
+                       || isSystemName (varName tv2)
                                -- Try to update sys-y type variables in preference to sig-y ones
 
        -- Second one isn't a type variable