@cached_property<EOL><INDENT>def is_orthonormal(self):<DEDENT>
a, b, c, d, e, f, g, h, i = self<EOL>return (<EOL>self.is_conformal<EOL>and abs(<NUM_LIT:1.0> - (a * a + d * d)) < EPSILON<EOL>and abs(<NUM_LIT:1.0> - (b * b + e * e)) < EPSILON<EOL>)<EOL>
True if the transform is orthonormal, which means that the
        transform represents a rigid motion, which has no effective scaling or
        shear. Mathematically, this means that the axis vectors of the
        transform matrix are perpendicular and unit-length.  Applying an
        orthonormal transform to a shape always results in a congruent shape.