If is Meromorphic in a region enclosed by a curve , let be the number of
Complex Roots of in , and be the number of Poles
in , then

Defining and gives

**References**

Duren, P.; Hengartner, W.; and Laugessen, R. S. ``The Argument Principle for Harmonic Functions.''
*Math. Mag.* **103**, 411-415, 1996.

© 1996-9

1999-05-25