src/HOL/SMT_Examples/boogie.ML

 
 fun parse_func cx arity n ls =
   let
     val ((Ts, atts), ls') =
       ls |> repeat (parse_type cx) arity ||>> repeat (parse_attr cx) n
-    val unique = member (=) atts "unique"
+    val unique = member (op =) atts "unique"
   in ((split_last Ts, unique), ls') end
 
 fun parse_decl (("type-decl" :: name :: _) :: ls) cx = (ls, add_type name cx)
   | parse_decl (["fun-decl", name, arity, n] :: ls) cx =
       let val (((Ts, T), unique), ls') = parse_func cx arity n ls