def pushquants(f):
# print('pushquant({0})'.format(f))
if is_quantified(f):
arg = f.args[0]
if arg.op == OP_NOT:
return ~pushquants(Quantifier(opposite(f.op), f.vars, arg.args[0]))
elif is_quantified(arg):
arg1 = pushquants(arg)
# did pushquants have any effect?
if arg1 == arg:
# # if no, see if changing the order of the quants has an effect
# arg2 = Quantifier(f.op, f.vars, arg.args[0])
# arg2_ = pushquants(arg2)
# if arg2 == arg2_:
# return Quantifier(f.op, f.vars, arg1)
# else:
# return Quantifier(arg.op, arg.vars, arg2_)
return Quantifier(f.op, f.vars, arg1)
else:
return pushquants(Quantifier(f.op, f.vars, arg1))
elif arg.op in [OP_AND, OP_OR]:
arg1 = arg.args[0]
arg2 = arg.args[1]
variable = f.vars[0]
if variable in fvars(arg1) and variable in fvars(arg2):
if ((arg.op == OP_AND and f.op == OP_FORALL) or
(arg.op == OP_OR and f.op == OP_EXISTS)):
return pushquants(Expr(arg.op,
Quantifier(f.op, f.vars, arg1),
Quantifier(f.op, f.vars, arg2)))
else:
return Quantifier(f.op, f.vars, pushquants(arg))
if variable in fvars(arg1):
return pushquants(Expr(arg.op,
Quantifier(f.op, f.vars, arg1), arg2))
if variable in fvars(arg2):
return pushquants(Expr(arg.op, arg1,
Quantifier(f.op, f.vars, arg2)))
else:
get_log().warning('Dropped quantifier "{0} : {1}" from "{2}"'
.format(f.op, f.vars, f))
return arg
elif arg.op == OP_IMPLIES:
arg1 = arg.args[0]
arg2 = arg.args[1]
variable = f.vars[0]
if variable in fvars(arg1) and variable in fvars(arg2):
return Quantifier(f.op, f.vars, pushquants(arg))
elif variable in fvars(arg1):
quant = opposite(f.op)
return (pushquants(Quantifier(quant, variable, arg1)) >>
pushquants(arg2))
elif variable in fvars(arg2):
return (pushquants(arg1) >>
pushquants(Quantifier(f.op, variable, arg2)))
else:
get_log().warning('Dropped quantifier "{0} : {1}" from "{2}"'
.format(f.op, f.vars, f))
return (pushquants(arg1) >> pushquants(arg2))
elif arg.op == OP_IMPLIED_BY:
arg1 = arg.args[0]
arg2 = arg.args[1]
variable = f.vars[0]
if variable in fvars(arg1) and variable in fvars(arg2):
return Quantifier(f.op, f.vars, pushquants(arg))
elif variable in fvars(arg1):
return (pushquants(Quantifier(f.op, variable, arg1)) <<
pushquants(arg2))
elif variable in fvars(arg2):
quant = opposite(f.op)
return (pushquants(arg1) <<
pushquants(Quantifier(quant, variable, arg2)))
else:
get_log().warning('Dropped quantifier "{0} : {1}" from "{2}"'
.format(f.op, f.vars, f))
return (pushquants(arg1) << pushquants(arg2))
else:
return Quantifier(f.op, f.vars[0], pushquants(f.args[0]))
elif f.op == OP_NOT:
return ~pushquants(f.args[0])
elif f.op in BINARY_LOGIC_OPS:
return Expr(f.op, *[pushquants(x) for x in f.args])
else:
return f
def pullquants(f):
# print('pullquants({0})'.format(str(f)))
if f.op == OP_AND:
arg1 = pullquants(f.args[0])
arg2 = pullquants(f.args[1])
if arg1.op == OP_FORALL and arg2.op == OP_FORALL:
return rename_and_pull(f, OP_FORALL,
arg1.vars[0], arg2.vars[0],
arg1.args[0], arg2.args[0])
elif is_quantified(arg1):
return rename_and_pull(f, arg1.op,
arg1.vars[0], None,
arg1.args[0], arg2)
elif is_quantified(arg2):
return rename_and_pull(f, arg2.op,
None, arg2.vars[0],
arg1, arg2.args[0])
else:
return (arg1 & arg2)
elif f.op == OP_OR:
arg1 = pullquants(f.args[0])
arg2 = pullquants(f.args[1])
if arg1.op == OP_EXISTS and arg2.op == OP_EXISTS:
return rename_and_pull(f, OP_EXISTS,
arg1.vars[0], arg2.vars[0],
arg1.args[0], arg2.args[0])
elif is_quantified(arg1):
return rename_and_pull(f, arg1.op,
arg1.vars[0], None,
arg1.args[0], arg2)
elif is_quantified(arg2):
return rename_and_pull(f, arg2.op,
None, arg2.vars[0],
arg1, arg2.args[0])
else:
return (arg1 | arg2)
elif f.op == OP_IMPLIES:
arg1 = pullquants(f.args[0])
arg2 = pullquants(f.args[1])
if is_quantified(arg1):
return rename_and_pull(f, opposite(arg1.op),
arg1.vars[0], None,
arg1.args[0], arg2)
elif is_quantified(arg2):
return rename_and_pull(f, arg2.op,
None, arg2.vars[0],
arg1, arg2.args[0])
else:
return (arg1 >> arg2)
elif f.op == OP_IMPLIED_BY:
arg1 = pullquants(f.args[0])
arg2 = pullquants(f.args[1])
if is_quantified(arg1):
return rename_and_pull(f, arg1.op,
arg1.vars[0], None,
arg1.args[0], arg2)
elif is_quantified(arg2):
return rename_and_pull(f, opposite(arg2.op),
None, arg2.vars[0],
arg1, arg2.args[0])
else:
return (arg1 << arg2)
elif f.op == OP_EQUIVALENT:
arg1 = pullquants(f.args[0])
arg2 = pullquants(f.args[1])
return pullquants((arg1 >> arg2) & (arg1 << arg2))
elif f.op == OP_NOT:
arg = pullquants(f.args[0])
if is_quantified(arg):
return Quantifier(opposite(arg.op), f.vars, ~(arg.args[0]))
else:
return (~arg)
else:
return f
