fact: Fixpoint plength (p: positive) : positive := match p with xH => xH | xO p1 => Pos.succ (plength p1) | xI p1 => Pos.succ (plength p1) end.
imports: ZArith Znumtheory Zpow_facts CyclicAxioms Cyclic63 Int63Compat Bignums(DoubleCyclic BigN) W Mod_op ZEll Bits Zmod