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#!/usr/bin/env python
###############################################################################
# Top contributors (to current version):
# Yoni Zohar, Aina Niemetz, Andrew Reynolds
#
# This file is part of the cvc5 project.
#
# Copyright (c) 2009-2025 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 cvc5
# sygus solver through the Python API. This is a direct
# translation of sygus-inv.cpp .
##
import utils
import cvc5
from cvc5 import Kind
if __name__ == "__main__":
tm = cvc5.TermManager()
slv = cvc5.Solver(tm)
# required options
slv.setOption("sygus", "true")
slv.setOption("incremental", "false")
# set the logic
slv.setLogic("LIA")
integer = tm.getIntegerSort()
boolean = tm.getBooleanSort()
zero = tm.mkInteger(0)
one = tm.mkInteger(1)
ten = tm.mkInteger(10)
# declare input variables for functions
x = tm.mkVar(integer, "x")
xp = tm.mkVar(integer, "xp")
# (ite (< x 10) (= xp (+ x 1)) (= xp x))
ite = tm.mkTerm(Kind.ITE,
tm.mkTerm(Kind.LT, x, ten),
tm.mkTerm(Kind.EQUAL, xp, tm.mkTerm(Kind.ADD, x, one)),
tm.mkTerm(Kind.EQUAL, xp, x))
# define the pre-conditions, transition relations, and post-conditions
pre_f = slv.defineFun("pre-f", [x], boolean, tm.mkTerm(Kind.EQUAL, x, zero))
trans_f = slv.defineFun("trans-f", [x, xp], boolean, ite)
post_f = slv.defineFun("post-f", [x], boolean, tm.mkTerm(Kind.LEQ, x, ten))
# declare the invariant-to-synthesize
inv_f = slv.synthFun("inv-f", [x], boolean)
slv.addSygusInvConstraint(inv_f, pre_f, trans_f, post_f)
# print solutions if available
if slv.checkSynth().hasSolution():
# Output should be equivalent to:
# (define-fun inv-f ((x Int)) Bool (not (>= x 11)))
terms = [inv_f]
utils.print_synth_solutions(terms, slv.getSynthSolutions(terms))
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