mathlib

372edc36 - feat (analysis/special_functions): limit formula and reflection formula for Gamma (#18404)

feat (analysis/special_functions): limit formula and reflection formula for Gamma (#18404) This adds Euler's limit formula and the reflection formula for the Gamma function. As a consequence we get that Gamma does not vanish on the complex plane (except at non-positive integers, where it is undefined, and we have arbitrarily chosen it to be 0).