mirror of
https://github.com/Z3Prover/z3
synced 2025-10-31 19:52:29 +00:00
87 lines
2.7 KiB
Python
87 lines
2.7 KiB
Python
# Copyright (c) Microsoft Corporation 2015
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from __future__ import print_function
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from z3 import *
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def visitor(e, seen):
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if e in seen:
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return
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seen[e] = True
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yield e
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if is_app(e):
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for ch in e.children():
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for e in visitor(ch, seen):
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yield e
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return
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if is_quantifier(e):
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for e in visitor(e.body(), seen):
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yield e
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return
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def modify(e, fn):
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seen = {}
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def visit(e):
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if e in seen:
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pass
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elif fn(e) is not None:
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seen[e] = fn(e)
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elif is_and(e):
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chs = [visit(ch) for ch in e.children()]
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seen[e] = And(chs)
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elif is_or(e):
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chs = [visit(ch) for ch in e.children()]
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seen[e] = Or(chs)
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elif is_app(e):
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chs = [visit(ch) for ch in e.children()]
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seen[e] = e.decl()(chs)
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elif is_quantifier(e):
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# Note: does not work for Lambda that requires a separate case
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body = visit(e.body())
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is_forall = e.is_forall()
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num_pats = e.num_patterns()
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pats = (Pattern * num_pats)()
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for i in range(num_pats):
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pats[i] = e.pattern(i).ast
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num_decls = e.num_vars()
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sorts = (Sort * num_decls)()
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names = (Symbol * num_decls)()
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for i in range(num_decls):
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sorts[i] = e.var_sort(i).ast
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names[i] = to_symbol(e.var_name(i), e.ctx)
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r = QuantifierRef(Z3_mk_quantifier(e.ctx_ref(), is_forall, e.weight(), num_pats, pats, num_decls, sorts, names, body.ast), e.ctx)
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seen[e] = r
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else:
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seen[e] = e
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return seen[e]
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return visit(e)
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if __name__ == "__main__":
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x, y = Ints('x y')
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fml = x + x + y > 2
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seen = {}
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for e in visitor(fml, seen):
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if is_const(e) and e.decl().kind() == Z3_OP_UNINTERPRETED:
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print("Variable", e)
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else:
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print(e)
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s = SolverFor("HORN")
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inv = Function('inv', IntSort(), IntSort(), BoolSort())
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i, ip, j, jp = Ints('i ip j jp')
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s.add(ForAll([i, j], Implies(i == 0, inv(i, j))))
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s.add(ForAll([i, ip, j, jp], Implies(And(inv(i, j), i < 10, ip == i + 1), inv(ip, jp))))
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s.add(ForAll([i, j], Implies(And(inv(i, j), i >= 10), i == 10)))
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a0, a1, a2 = Ints('a0 a1 a2')
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b0, b1, b2 = Ints('b0 b1 b2')
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x = Var(0, IntSort())
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y = Var(1, IntSort())
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template = And(a0 + a1*x + a2*y >= 0, b0 + b1*x + b2*y >= 0)
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def update(e):
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if is_app(e) and eq(e.decl(), inv):
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return substitute_vars(template, (e.arg(0)), e.arg(1))
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return None
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for f in s.assertions():
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f_new = modify(f, update)
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print(f_new)
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