def _is_negative_or_zero(term):
if getattr(term, 'is_number', False):
return term <= 0
elif isinstance(term, Pow):
if term.args[1]%2==1:
return _is_negative_or_zero(term.args[0])
t = Poly(term).as_dict()
if (all(c < 0 for c in t.values()) and
all(i % 2 == 0 for d in t.keys() for i in d)):
return True
return ask_is_negative(term)
def _is_negative(term):
if getattr(term, 'is_number', False):
return term < 0
elif isinstance(term, Pow):
if term.args[1]%2==1:
return _is_negative(term.args[0])
else:
return False
l = len(term.free_symbols)
t = Poly(term).as_dict()
if (all(c < 0 for c in t.values()) and
all(i % 2 == 0 for d in t.keys() for i in d) and
(0,)*l in t.keys()):
return True
return ask_is_negative(term)
