diff --git a/grammars/logic/Logic.gf b/grammars/logic/Logic.gf
index aed631f04..41fd5cef8 100644
--- a/grammars/logic/Logic.gf
+++ b/grammars/logic/Logic.gf
@@ -81,7 +81,7 @@ def
   ImplE _ _ (ImplI _ _ b) a = b a ;
   NegE _ (NegI _ b) a = b a ;
   UnivE _ _ (UnivI _ _ b) a = b a ;
-  ExistE _ _ _ (ExistI A B a b) d = d a b ;
+  ExistE _ _ _ (ExistI _ _ a b) d = d a b ;
 
   -- Hypo and Pron are identities
   Hypo _ a = a ;
diff --git a/src/GF/Grammar/TypeCheck.hs b/src/GF/Grammar/TypeCheck.hs
index 8d36d1ab3..a029235a8 100644
--- a/src/GF/Grammar/TypeCheck.hs
+++ b/src/GF/Grammar/TypeCheck.hs
@@ -75,9 +75,9 @@ computeVal gr v = case v of
 splitConstraints :: Constraints -> (Constraints,MetaSubst)
 splitConstraints cs = csmsu where
 
-  csmsu     = (nub [(a,b) | (a,b) <- csf,a /= b],msf)
-  csmsu0    = unif (csf,msf)  -- alternative: filter first
-  (csf,msf) = foldr mkOne ([],[]) cs
+  csmsu       = (nub [(a,b) | (a,b) <- csf1,a /= b],msf1)
+  (csf1,msf1) = unif (csf,msf)  -- alternative: filter first
+  (csf,msf)   = foldr mkOne ([],[]) cs
 
   csmsf     = foldr mkOne ([],msu) csu
   (csu,msu) = unif (cs,[])    -- alternative: unify first