def test_times_algebraic(self):
from pysmt.constants import Numeral
env = get_env()
mgr = env.formula_manager
r0 = Symbol("r0", REAL)
p_2 = Real(2)
m_5 = mgr._Algebraic(Numeral(-5))
m_10 = mgr._Algebraic(Numeral(-10))
# -5 * r0 * 2
expr = Times(m_5, r0, p_2)
res = expr.simplify()
self.assertValid(Equals(expr, res))
self.assertIn(m_10, res.args())
def test_plus_algebraic(self):
from pysmt.constants import Numeral
env = get_env()
mgr = env.formula_manager
r0 = Symbol("r0", REAL)
p_2 = Real(2)
m_5 = mgr._Algebraic(Numeral(-5))
m_3 = mgr._Algebraic(Numeral(-3))
# r0 + 2 - 5
expr = Plus(r0, p_2, m_5)
res = expr.simplify()
self.assertValid(Equals(expr, res))
self.assertIn(m_3, res.args())
def walk_minus(self, formula, args, **kwargs):
assert len(args) == 2
sl = args[0]
sr = args[1]
if sl.is_real_constant() and sr.is_real_constant():
l = sl.constant_value()
r = sr.constant_value()
return self.manager.Real(l - r)
if sl.is_int_constant() and sr.is_int_constant():
l = sl.constant_value()
r = sr.constant_value()
return self.manager.Int(l - r)
if sl.is_algebraic_constant() and \
sr.is_algebraic_constant():
from pysmt.constants import Numeral
l = sl.constant_value()
r = sr.constant_value()
return self.mananger._Algebraic(Numeral(l - r))
if sr.is_constant() and sr.is_zero():
return sl
if sl == sr:
if self.env.stc.walk(sl) == types.REAL:
return self.manager.Real(0)
else:
return self.manager.Int(0)
return self.manager.Minus(sl, sr)
def walk_pow(self, formula, args, **kwargs):
if args[0].is_real_constant():
l = args[0].constant_value()
r = args[1].constant_value()
return self.manager.Real(l**r)
if args[0].is_int_constant():
l = args[0].constant_value()
r = args[1].constant_value()
return self.manager.Int(l**r)
if args[0].is_algebraic_constant():
from pysmt.constants import Numeral
l = args[0].constant_value()
r = args[1].constant_value()
return self.manager._Algebraic(Numeral(l**r))
return self.manager.Pow(args[0], args[1])
def walk_times(self, formula, args, **kwargs):
new_args = []
constant_mul = 1
stack = list(args)
ttype = self.env.stc.get_type(args[0])
is_algebraic = False
while len(stack) > 0:
x = stack.pop()
if x.is_constant():
if x.is_algebraic_constant():
is_algebraic = True
if x.is_zero():
constant_mul = 0
break
else:
constant_mul *= x.constant_value()
elif x.is_times():
stack += x.args()
else:
new_args.append(x)
const = None
if is_algebraic:
from pysmt.constants import Numeral
const = self.manager._Algebraic(Numeral(constant_mul))
elif ttype.is_real_type():
const = self.manager.Real(constant_mul)
else:
assert ttype.is_int_type()
const = self.manager.Int(constant_mul)
if const.is_zero():
return const
else:
if len(new_args) == 0:
return const
elif not const.is_one():
new_args.append(const)
new_args = sorted(new_args, key=FNode.node_id)
return self.manager.Times(new_args)
def _back_single_term(self, expr, args, model=None):
assert z3.is_expr(expr)
if z3.is_quantifier(expr):
raise NotImplementedError(
"Quantified back conversion is currently not supported")
assert not len(args) > 2 or \
(z3.is_and(expr) or z3.is_or(expr) or
z3.is_add(expr) or z3.is_mul(expr) or
(len(args) == 3 and (z3.is_ite(expr) or z3.is_array_store(expr)))),\
"Unexpected n-ary term: %s" % expr
res = None
try:
decl = z3.Z3_get_app_decl(expr.ctx_ref(), expr.as_ast())
kind = z3.Z3_get_decl_kind(expr.ctx.ref(), decl)
# Try to get the back-conversion function for the given Kind
fun = self._back_fun[kind]
return fun(args, expr)
except KeyError as ex:
pass
if z3.is_const(expr):
# Const or Symbol
if z3.is_rational_value(expr):
n = expr.numerator_as_long()
d = expr.denominator_as_long()
f = Fraction(n, d)
return self.mgr.Real(f)
elif z3.is_int_value(expr):
n = expr.as_long()
return self.mgr.Int(n)
elif z3.is_bv_value(expr):
n = expr.as_long()
w = expr.size()
return self.mgr.BV(n, w)
elif z3.is_as_array(expr):
if model is None:
raise NotImplementedError("As-array expressions cannot be" \
" handled as they are not " \
"self-contained")
else:
interp_decl = z3.get_as_array_func(expr)
interp = model[interp_decl]
default = self.back(interp.else_value(), model=model)
assign = {}
for i in xrange(interp.num_entries()):
e = interp.entry(i)
assert e.num_args() == 1
idx = self.back(e.arg_value(0), model=model)
val = self.back(e.value(), model=model)
assign[idx] = val
arr_type = self._z3_to_type(expr.sort())
return self.mgr.Array(arr_type.index_type, default, assign)
elif z3.is_algebraic_value(expr):
# Algebraic value
return self.mgr._Algebraic(Numeral(expr))
else:
# it must be a symbol
try:
return self.mgr.get_symbol(str(expr))
except UndefinedSymbolError:
import warnings
symb_type = self._z3_to_type(expr.sort())
warnings.warn("Defining new symbol: %s" % str(expr))
return self.mgr.FreshSymbol(symb_type, template="__z3_%d")
elif z3.is_function(expr):
# This needs to be after we try to convert regular Symbols
fsymbol = self.mgr.get_symbol(expr.decl().name())
return self.mgr.Function(fsymbol, args)
# If we reach this point, we did not manage to translate the expression
raise ConvertExpressionError(message=("Unsupported expression: %s" %
(str(expr))),
expression=expr)
def walk_plus(self, formula, args, **kwargs):
to_sum = []
to_sub = []
constant_add = 0
stack = list(args)
ttype = self.env.stc.get_type(args[0])
is_algebraic = False
while len(stack) > 0:
x = stack.pop()
if x.is_constant():
if x.is_algebraic_constant():
is_algebraic = True
constant_add += x.constant_value()
elif x.is_plus():
stack += x.args()
elif x.is_minus():
to_sum.append(x.arg(0))
to_sub.append(x.arg(1))
elif x.is_times() and x.args()[-1].is_constant():
const = x.args()[-1]
const_val = const.constant_value()
if const_val < 0:
new_times = list(x.args()[:-1])
if const_val != -1:
const_val = -const_val
if const.is_algebraic_constant():
from pysmt.constants import Numeral
const = self.manager._Algebraic(Numeral(const_val))
elif ttype.is_real_type():
const = self.manager.Real(const_val)
else:
assert ttype.is_int_type()
const = self.manager.Int(const_val)
new_times.append(const)
new_times = self.manager.Times(new_times)
to_sub.append(new_times)
else:
to_sum.append(x)
else:
to_sum.append(x)
const = None
if is_algebraic:
from pysmt.constants import Numeral
const = self.manager._Algebraic(Numeral(constant_add))
elif ttype.is_real_type():
const = self.manager.Real(constant_add)
else:
assert ttype.is_int_type()
const = self.manager.Int(constant_add)
if len(to_sum) == 0 and len(to_sub) == 0:
return const
if not const.is_zero():
to_sum.append(const)
assert to_sum or to_sub
res = self.manager.Plus(to_sum) if to_sum else None
if to_sub:
sub = self.manager.Plus(to_sub)
if res:
res = self.manager.Minus(res, sub)
else:
if ttype.is_int_type():
m_1 = self.manager.Int(-1)
else:
assert ttype.is_real_type()
m_1 = self.manager.Real(-1)
res = self.manager.Times(m_1, sub)
return res
