From: Morgan Deters <mdeters@cs.nyu.edu>
Date: Fri, 17 May 2013 15:18:12 +0000 (-0400)
Subject: As per SMT-LIB standard: make - and xor take n>2 args and be left-assoc; => takes... 
X-Git-Tag: cvc5-1.0.0~7287^2~33^2~18
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=3913e813456fc6cabb1208044fd36c92c0056385;p=cvc5.git

As per SMT-LIB standard: make - and xor take n>2 args and be left-assoc; => takes n>2 args and is right-assoc.

Thanks to David Cok for pointing out this issue.
---

diff --git a/src/parser/smt2/Smt2.g b/src/parser/smt2/Smt2.g
index dbe1135b3..7c0c1aad3 100644
--- a/src/parser/smt2/Smt2.g
+++ b/src/parser/smt2/Smt2.g
@@ -711,13 +711,27 @@ term[CVC4::Expr& expr, CVC4::Expr& expr2]
       } else if( CVC4::kind::isAssociative(kind) &&
                  args.size() > EXPR_MANAGER->maxArity(kind) ) {
     	/* Special treatment for associative operators with lots of children */
-        expr = EXPR_MANAGER->mkAssociative(kind,args);
+        expr = EXPR_MANAGER->mkAssociative(kind, args);
       } else if( kind == CVC4::kind::MINUS && args.size() == 1 ) {
         expr = MK_EXPR(CVC4::kind::UMINUS, args[0]);
+      } else if( ( kind == CVC4::kind::XOR || kind == CVC4::kind::MINUS ) &&
+                 args.size() > 2 ) {
+        /* left-associative, but CVC4 internally only supports 2 args */
+        expr = args[0];
+        for(size_t i = 1; i < args.size(); ++i) {
+          expr = MK_EXPR(kind, expr, args[i]);
+        }
+      } else if( kind == CVC4::kind::IMPLIES && args.size() > 2 ) {
+        /* right-associative, but CVC4 internally only supports 2 args */
+        expr = args[args.size() - 1];
+        for(size_t i = args.size() - 1; i > 0;) {
+          expr = MK_EXPR(kind, args[--i], expr);
+        }
       } else if( ( kind == CVC4::kind::IFF || kind == CVC4::kind::EQUAL ||
                    kind == CVC4::kind::LT || kind == CVC4::kind::GT ||
                    kind == CVC4::kind::LEQ || kind == CVC4::kind::GEQ ) &&
                  args.size() > 2 ) {
+        /* "chainable", but CVC4 internally only supports 2 args */
         expr = MK_EXPR(CVC4::kind::CHAIN, MK_CONST(kind), args);
       } else {
         PARSER_STATE->checkOperator(kind, args.size());