[sledge] Fix type of Context.fold_uses_of

Reviewed By: jvillard

Differential Revision: D25756581

fbshipit-source-id: afb0e0509

sledge/src/fol/context.ml

@@ -710,7 +710,7 @@ let fold_uses_of r t s ~f =
   let rec fold_ e s ~f =
     let s =
       Iter.fold (Trm.trms e) s ~f:(fun sub s ->
-          if Trm.equal t sub then f s e else s )
+          if Trm.equal t sub then f e s else s )
     in
     if is_interpreted e then Iter.fold ~f:(fold_ ~f) (Trm.trms e) s else s
   in
@@ -1053,10 +1053,11 @@ let solve_concat_extracts_eq r x =
   [%Trace.call fun {pf} -> pf "%a@ %a" Trm.pp x pp r]
   ;
   let uses =
-    fold_uses_of r x [] ~f:(fun uses -> function
+    fold_uses_of r x [] ~f:(fun use uses ->
+        match use with
         | Sized _ as m ->
-          fold_uses_of r m uses ~f:(fun uses -> function
+            fold_uses_of r m uses ~f:(fun use uses ->
-            | Extract _ as e -> e :: uses | _ -> uses )
+                match use with Extract _ as e -> e :: uses | _ -> uses )
         | _ -> uses )
   in
   let find_extracts_at_off off =