1 files changed, 97 insertions, 0 deletions
diff --git a/examples/api/cpp/bitvectors_and_arrays.cpp b/examples/api/cpp/bitvectors_and_arrays.cpp
new file mode 100644
index 000000000..547b294a0
--- /dev/null
+++ b/examples/api/cpp/bitvectors_and_arrays.cpp
@@ -0,0 +1,97 @@
+/******************************************************************************
+ * Top contributors (to current version):
+ *   Aina Niemetz, Liana Hadarean
+ *
+ * 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 solving capabilities of the CVC4
+ * bit-vector and array solvers.
+ *
+ */
+
+#include <cvc5/cvc5.h>
+
+#include <cmath>
+#include <iostream>
+
+using namespace std;
+using namespace cvc5::api;
+
+int main()
+{
+  Solver slv;
+  slv.setOption("produce-models", "true");      // Produce Models
+  slv.setOption("output-language", "smtlib"); // output-language
+  slv.setLogic("QF_AUFBV");                   // Set the logic
+
+  // Consider the following code (where size is some previously defined constant):
+  //
+  //
+  //   Assert (current_array[0] > 0);
+  //   for (unsigned i = 1; i < k; ++i) {
+  //     current_array[i] = 2 * current_array[i - 1];
+  //     Assert (current_array[i-1] < current_array[i]);
+  //     }
+  //
+  // We want to check whether the assertion in the body of the for loop holds
+  // throughout the loop.
+
+  // Setting up the problem parameters
+  unsigned k = 4;                // number of unrollings (should be a power of 2)
+  unsigned index_size = log2(k); // size of the index
+
+
+  // Sorts
+  Sort elementSort = slv.mkBitVectorSort(32);
+  Sort indexSort = slv.mkBitVectorSort(index_size);
+  Sort arraySort = slv.mkArraySort(indexSort, elementSort);
+
+  // Variables
+  Term current_array = slv.mkConst(arraySort, "current_array");
+
+  // Making a bit-vector constant
+  Term zero = slv.mkBitVector(index_size, 0u);
+
+  // Asserting that current_array[0] > 0
+  Term current_array0 = slv.mkTerm(SELECT, current_array, zero);
+  Term current_array0_gt_0 = slv.mkTerm(
+      BITVECTOR_SGT, current_array0, slv.mkBitVector(32, 0u));
+  slv.assertFormula(current_array0_gt_0);
+
+  // Building the assertions in the loop unrolling
+  Term index = slv.mkBitVector(index_size, 0u);
+  Term old_current = slv.mkTerm(SELECT, current_array, index);
+  Term two = slv.mkBitVector(32, 2u);
+
+  std::vector<Term> assertions;
+  for (unsigned i = 1; i < k; ++i) {
+    index = slv.mkBitVector(index_size, i);
+    Term new_current = slv.mkTerm(BITVECTOR_MULT, two, old_current);
+    // current[i] = 2 * current[i-1]
+    current_array = slv.mkTerm(STORE, current_array, index, new_current);
+    // current[i-1] < current [i]
+    Term current_slt_new_current = slv.mkTerm(BITVECTOR_SLT, old_current, new_current);
+    assertions.push_back(current_slt_new_current);
+
+    old_current = slv.mkTerm(SELECT, current_array, index);
+  }
+
+  Term query = slv.mkTerm(NOT, slv.mkTerm(AND, assertions));
+
+  cout << "Asserting " << query << " to CVC4 " << endl;
+  slv.assertFormula(query);
+  cout << "Expect sat. " << endl;
+  cout << "CVC4: " << slv.checkSatAssuming(slv.mkTrue()) << endl;
+
+  // Getting the model
+  cout << "The satisfying model is: " << endl;
+  cout << "  current_array = " << slv.getValue(current_array) << endl;
+  cout << "  current_array[0] = " << slv.getValue(current_array0) << endl;
+  return 0;
+}