fact: Fixpoint IPR p {struct p}: R := match p with xH => ring1 | xO xH => 1+1 | xO p1 => R2*(IPR p1) | xI xH => 1+(1+1) | xI p1 => 1+(R2*(IPR p1)) end.
imports: List Setoid BinPos BinList Znumtheory Morphisms Setoid Bool Algebra_syntax Ncring Ncring_initial Ncring_tac Integral_domain ZArith Lia