def as_set(self):
"""
Rewrite logic operators and relationals in terms of real sets.
Examples
========
>>> from sympy import And, Symbol
>>> x = Symbol('x', real=True)
>>> And(x<2, x>-2).as_set()
(-2, 2)
"""
from sympy.core.sets import Intersection
if len(self.free_symbols) == 1:
return Intersection(*[arg.as_set() for arg in self.args])
else:
raise NotImplementedError("Sorry, And.as_set has not yet been"
" implemented for multivariate"
" expressions")
def _intersect(self, other):
if other.is_Interval:
return Intersection(S.Integers, other, Interval(1, oo))
return None
def _intersect(self, other):
if other.is_Interval:
return Intersection(S.Integers, other,
Interval(self._inf, S.Infinity))
return None