Paul Rubin wrote: > Also, for > example, the derivative of a complex valued function means something > considerably stronger than the derivative of a real valued function.
I vaguely remember (it has been decades) an amazingly beautiful russian doll system of four of five theorems, the first hypothesizing a function of a complex variable with a property that IIRC appeared somewhat weaker than differentiability, and the latter theorems not hypothesizing anything more, but pushing the consequence further to ever stronger properties. -- http://mail.python.org/mailman/listinfo/python-list
