em>.
                    In the case of a simple closed contour $C,$
                    the <em>positive</em> direction corresponds
                    to the <em>counterclockwise</em> direction.
                    For example, the circle $z(t) = e^{it},$ $0 \leq t \leq 2\pi,$
                    has positive orientation.
                    The <em>negative direction</em> on a contour $C$ is
                    the direction opposite the positive direction. If $C$ has an orientation,
                    