def is_perpendicular(l1, l2):
        """Are two linear entities perpendicular?

        Parameters
        ==========

        l1 : LinearEntity
        l2 : LinearEntity

        Returns
        =======

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

        See Also
        ========

        coefficients

        Examples
        ========

        >>> from sympy import Point, Line
        >>> p1, p2, p3 = Point(0, 0), Point(1, 1), Point(-1, 1)
        >>> l1, l2 = Line(p1, p2), Line(p1, p3)
        >>> l1.is_perpendicular(l2)
        True

        >>> p4 = Point(5, 3)
        >>> l3 = Line(p1, p4)
        >>> l1.is_perpendicular(l3)
        False

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