[matching Vars are only ignore if they have the same name and type!
martin.hofmann@uni-bamberg.de**20100108082115] hunk ./src/Syntax/UnifyExp.hs 28
-    match s@(TVarE i1 _) t@(TVarE i2 _)     = do 
+    match s@(TVarE i1 t1) t@(TVarE i2 t2)     = do 
hunk ./src/Syntax/UnifyExp.hs 30
-        if i1 == i2 then return nullSubst else return (i2 <~ s)
+        if (i1 == i2) && (t1 == t2) then return nullSubst else return (i2 <~ s)
+--        checkMatch s t >> return (i2 <~ s) -- is wrong but works better