1 files changed, 142 insertions, 0 deletions
diff --git a/examples/api/cpp/sygus-fun.cpp b/examples/api/cpp/sygus-fun.cpp
new file mode 100644
index 000000000..0f96e72a7
--- /dev/null
+++ b/examples/api/cpp/sygus-fun.cpp
@@ -0,0 +1,142 @@
+/******************************************************************************
+ * Top contributors (to current version):
+ *   Abdalrhman Mohamed, Mudathir Mohamed, Aina Niemetz
+ *
+ * This file is part of the cvc5 project.
+ *
+ * Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
+ * in the top-level source directory and their institutional affiliations.
+ * All rights reserved.  See the file COPYING in the top-level source
+ * directory for licensing information.
+ * ****************************************************************************
+ *
+ * A simple demonstration of the Sygus API.
+ *
+ * A simple demonstration of how to use the Sygus API to synthesize max and min
+ * functions. Here is the same problem written in Sygus V2 format:
+ *
+ * (set-logic LIA)
+ *
+ * (synth-fun max ((x Int) (y Int)) Int
+ *   ((Start Int) (StartBool Bool))
+ *   ((Start Int (0 1 x y
+ *                (+ Start Start)
+ *                (- Start Start)
+ *                (ite StartBool Start Start)))
+ *    (StartBool Bool ((and StartBool StartBool)
+ *                     (not StartBool)
+ *                     (<= Start Start)))))
+ *
+ * (synth-fun min ((x Int) (y Int)) Int)
+ *
+ * (declare-var x Int)
+ * (declare-var y Int)
+ *
+ * (constraint (>= (max x y) x))
+ * (constraint (>= (max x y) y))
+ * (constraint (or (= x (max x y))
+ *                 (= y (max x y))))
+ * (constraint (= (+ (max x y) (min x y))
+ *                (+ x y)))
+ *
+ * (check-synth)
+ *
+ * The printed output for this example should be equivalent to:
+ * (
+ *   (define-fun max ((x Int) (y Int)) Int (ite (<= x y) y x))
+ *   (define-fun min ((x Int) (y Int)) Int (ite (<= x y) x y))
+ * )
+ */
+
+#include <cvc5/cvc5.h>
+
+#include <iostream>
+
+#include "utils.h"
+
+using namespace cvc5::api;
+
+int main()
+{
+  Solver slv;
+
+  // required options
+  slv.setOption("lang", "sygus2");
+  slv.setOption("incremental", "false");
+
+  // set the logic
+  slv.setLogic("LIA");
+
+  Sort integer = slv.getIntegerSort();
+  Sort boolean = slv.getBooleanSort();
+
+  // declare input variables for the functions-to-synthesize
+  Term x = slv.mkVar(integer, "x");
+  Term y = slv.mkVar(integer, "y");
+
+  // declare the grammar non-terminals
+  Term start = slv.mkVar(integer, "Start");
+  Term start_bool = slv.mkVar(boolean, "StartBool");
+
+  // define the rules
+  Term zero = slv.mkInteger(0);
+  Term one = slv.mkInteger(1);
+
+  Term plus = slv.mkTerm(PLUS, start, start);
+  Term minus = slv.mkTerm(MINUS, start, start);
+  Term ite = slv.mkTerm(ITE, start_bool, start, start);
+
+  Term And = slv.mkTerm(AND, start_bool, start_bool);
+  Term Not = slv.mkTerm(NOT, start_bool);
+  Term leq = slv.mkTerm(LEQ, start, start);
+
+  // create the grammar object
+  Grammar g = slv.mkSygusGrammar({x, y}, {start, start_bool});
+
+  // bind each non-terminal to its rules
+  g.addRules(start, {zero, one, x, y, plus, minus, ite});
+  g.addRules(start_bool, {And, Not, leq});
+
+  // declare the functions-to-synthesize. Optionally, provide the grammar
+  // constraints
+  Term max = slv.synthFun("max", {x, y}, integer, g);
+  Term min = slv.synthFun("min", {x, y}, integer);
+
+  // declare universal variables.
+  Term varX = slv.mkSygusVar(integer, "x");
+  Term varY = slv.mkSygusVar(integer, "y");
+
+  Term max_x_y = slv.mkTerm(APPLY_UF, max, varX, varY);
+  Term min_x_y = slv.mkTerm(APPLY_UF, min, varX, varY);
+
+  // add semantic constraints
+  // (constraint (>= (max x y) x))
+  slv.addSygusConstraint(slv.mkTerm(GEQ, max_x_y, varX));
+
+  // (constraint (>= (max x y) y))
+  slv.addSygusConstraint(slv.mkTerm(GEQ, max_x_y, varY));
+
+  // (constraint (or (= x (max x y))
+  //                 (= y (max x y))))
+  slv.addSygusConstraint(slv.mkTerm(
+      OR, slv.mkTerm(EQUAL, max_x_y, varX), slv.mkTerm(EQUAL, max_x_y, varY)));
+
+  // (constraint (= (+ (max x y) (min x y))
+  //                (+ x y)))
+  slv.addSygusConstraint(slv.mkTerm(
+      EQUAL, slv.mkTerm(PLUS, max_x_y, min_x_y), slv.mkTerm(PLUS, varX, varY)));
+
+  // print solutions if available
+  if (slv.checkSynth().isUnsat())
+  {
+    // Output should be equivalent to:
+    // (
+    //   (define-fun max ((x Int) (y Int)) Int (ite (<= x y) y x))
+    //   (define-fun min ((x Int) (y Int)) Int (ite (<= x y) x y))
+    // )
+    std::vector<Term> terms = {max, min};
+    printSynthSolutions(terms, slv.getSynthSolutions(terms));
+  }
+
+  return 0;
+}