(self, other, symbol=None)
return self.subs(dummy, tmp) == other.subs(symbol, tmp)
Compare two expressions and handle dummy symbols.

        Examples
        ========

        >>> from sympy import Dummy
        >>> from sympy.abc import x, y

        >>> u = Dummy('u')

        >>> (u**2 + 1).dummy_eq(x**2 + 1)
        True
        >>> (u**2 + 1) == (x**2 + 1)
        False

        >>> (u**2 + y).dummy_eq(x**2 + y, x)
        True
        >>> (u**2 + y).dummy_eq(x**2 + y, y)
        False
Compare two expressions and handle dummy symbols.
Compare two expressions and handle dummy symbols .
def dummy_eq(self, other, symbol=None):
        """
        Compare two expressions and handle dummy symbols.

        Examples
        ========

        >>> from sympy import Dummy
        >>> from sympy.abc import x, y

        >>> u = Dummy('u')

        >>> (u**2 + 1).dummy_eq(x**2 + 1)
        True
        >>> (u**2 + 1) == (x**2 + 1)
        False

        >>> (u**2 + y).dummy_eq(x**2 + y, x)
        True
        >>> (u**2 + y).dummy_eq(x**2 + y, y)
        False

        """
        dummy_symbols = [ s for s in self.free_symbols if s.is_Dummy ]

        if not dummy_symbols:
            return self == other
        elif len(dummy_symbols) == 1:
            dummy = dummy_symbols.pop()
        else:
            raise ValueError(
                "only one dummy symbol allowed on the left-hand side")

        if symbol is None:
            symbols = other.free_symbols

            if not symbols:
                return self == other
            elif len(symbols) == 1:
                symbol = symbols.pop()
            else:
                raise ValueError("specify a symbol in which expressions should be compared")

        tmp = dummy.__class__()

        return self.subs(dummy, tmp) == other.subs(symbol, tmp)
def dummy_eq ( self , other , symbol = None ) : dummy_symbols = [ s for s in self . free_symbols if s . is_Dummy ] if not dummy_symbols : return self == other elif len ( dummy_symbols ) == 1 : dummy = dummy_symbols . pop ( ) else : raise ValueError ( "only one dummy symbol allowed on the left-hand side" ) if symbol is None : symbols = other . free_symbols if not symbols : return self == other elif len ( symbols ) == 1 : symbol = symbols . pop ( ) else : raise ValueError ( "specify a symbol in which expressions should be compared" ) tmp = dummy . __class__ ( ) return self . subs ( dummy , tmp ) == other . subs ( symbol , tmp )