(cls, lhs, rhs)
Takes the difference between lhs and rhs, simplifies and evaluates.

        If the difference can be simplified to a single real number, it will
        be evaluated with ``cls._eval_relation``.  If the difference does not
        simplify or cannot be calculated, None will be returned.
Takes the difference between lhs and rhs, simplifies and evaluates.
Takes the difference between lhs and rhs simplifies and evaluates .
def _eval_sides(cls, lhs, rhs):
        """Takes the difference between lhs and rhs, simplifies and evaluates.

        If the difference can be simplified to a single real number, it will
        be evaluated with ``cls._eval_relation``.  If the difference does not
        simplify or cannot be calculated, None will be returned.

        """
        if isinstance(lhs, Expr) and isinstance(rhs, Expr):
            diff = lhs - rhs
            if not diff.has(Symbol):
                know = diff.equals(0)
                if know == True:
                    diff = S.Zero
                elif know == False:
                    diff = diff.evalf()
            if diff.is_Number and diff.is_real:
                return cls._eval_relation(diff, S.Zero)
def _eval_sides ( cls , lhs , rhs ) : if isinstance ( lhs , Expr ) and isinstance ( rhs , Expr ) : diff = lhs - rhs if not diff . has ( Symbol ) : know = diff . equals ( 0 ) if know == True : diff = S . Zero elif know == False : diff = diff . evalf ( ) if diff . is_Number and diff . is_real : return cls . _eval_relation ( diff , S . Zero )