Principal Abel function

From Hyperoperations Wiki
Jump to: navigation, search

The principal Abel function (up to an additive constant) of $f$ at fixpoint $a$ is the Abel function of $f$ such that the fractional iterates $\ph$ defined by $$\ph(x) = \alpha^{-1}(c+\alpha(x)), c\in\Q$$ are regular at the fixpoint $a$.