def is_parallel(l1, l2):
        """Are two linear entities parallel?

        Parameters
        ==========

        l1 : LinearEntity
        l2 : LinearEntity

        Returns
        =======

        True : if l1 and l2 are parallel,
        False : otherwise.

        See Also
        ========

        coefficients

        Examples
        ========

        >>> from sympy import Point, Line
        >>> p1, p2 = Point(0, 0), Point(1, 1)
        >>> p3, p4 = Point(3, 4), Point(6, 7)
        >>> l1, l2 = Line(p1, p2), Line(p3, p4)
        >>> Line.is_parallel(l1, l2)
        True

        >>> p5 = Point(6, 6)
        >>> l3 = Line(p3, p5)
        >>> Line.is_parallel(l1, l3)
        False

        """
        try:
            a1, b1, c1 = l1.coefficients
            a2, b2, c2 = l2.coefficients
            return bool(simplify(a1*b2 - b1*a2) == 0)
        except __HOLE__:
            return False
dataset/ETHPy150Open sympy/sympy/sympy/geometry/line.py/LinearEntity.is_parallel