Remove front-end support for Chain (#3767)

4 files changed, 33 insertions, 2 deletions

diff --git a/src/parser/parser.cpp b/src/parser/parser.cpp
index 32d555718..664fa209d 100644
--- a/src/parser/parser.cpp
+++ b/src/parser/parser.cpp
@@ -515,6 +515,22 @@ Expr Parser::mkHoApply(Expr expr, std::vector<Expr>& args)
   return expr;
 }
 
+api::Term Parser::mkChain(api::Kind k, const std::vector<api::Term>& args)
+{
+  if (args.size() == 2)
+  {
+    // if this is the case exactly 1 pair will be generated so the
+    // AND is not required
+    return d_solver->mkTerm(k, args[0], args[1]);
+  }
+  std::vector<api::Term> children;
+  for (size_t i = 0, nargsmo = args.size() - 1; i < nargsmo; i++)
+  {
+    children.push_back(d_solver->mkTerm(k, args[i], args[i + 1]));
+  }
+  return d_solver->mkTerm(api::AND, children);
+}
+
 bool Parser::isDeclared(const std::string& name, SymbolType type) {
   switch (type) {
     case SYM_VARIABLE:
diff --git a/src/parser/parser.h b/src/parser/parser.h
index ecf1e2961..cd70fde0f 100644
--- a/src/parser/parser.h
+++ b/src/parser/parser.h
@@ -24,6 +24,7 @@
 #include <set>
 #include <string>
 
+#include "api/cvc4cpp.h"
 #include "expr/expr.h"
 #include "expr/expr_stream.h"
 #include "expr/kind.h"
@@ -677,6 +678,16 @@ public:
    */
   Expr mkHoApply(Expr expr, std::vector<Expr>& args);
 
+  /** make chain
+   *
+   * Given a kind k and argument terms t_1, ..., t_n, this returns the
+   * conjunction of:
+   *  (k t_1 t_2) .... (k t_{n-1} t_n)
+   * It is expected that k is a kind denoting a predicate, and args is a list
+   * of terms of size >= 2 such that the terms above are well-typed.
+   */
+  api::Term mkChain(api::Kind k, const std::vector<api::Term>& args);
+
   /**
    * Add an operator to the current legal set.
    *
diff --git a/src/parser/smt2/smt2.cpp b/src/parser/smt2/smt2.cpp
index f3b66643a..11dedb259 100644
--- a/src/parser/smt2/smt2.cpp
+++ b/src/parser/smt2/smt2.cpp
@@ -1887,7 +1887,9 @@ Expr Smt2::applyParseOp(ParseOp& p, std::vector<Expr>& args)
                || kind == kind::LEQ || kind == kind::GEQ)
       {
         /* "chainable", but CVC4 internally only supports 2 args */
-        return em->mkExpr(em->mkConst(Chain(kind)), args);
+        api::Term ret =
+            mkChain(intToExtKind(kind), api::exprVectorToTerms(args));
+        return ret.getExpr();
       }
     }
 
diff --git a/src/parser/tptp/tptp.cpp b/src/parser/tptp/tptp.cpp
index 71a3e4bee..bf699ae3c 100644
--- a/src/parser/tptp/tptp.cpp
+++ b/src/parser/tptp/tptp.cpp
@@ -326,7 +326,9 @@ Expr Tptp::applyParseOp(ParseOp& p, std::vector<Expr>& args)
           || kind == kind::LEQ || kind == kind::GEQ)
       {
         /* "chainable", but CVC4 internally only supports 2 args */
-        return em->mkExpr(em->mkConst(Chain(kind)), args);
+        api::Term ret =
+            mkChain(intToExtKind(kind), api::exprVectorToTerms(args));
+        return ret.getExpr();
       }
     }