fact: Fixpoint T1add x y := if x is cons a n b then if y is cons a' n' b' then if a < a' then cons a' n' b' else if a' < a then (cons a n (b + (cons a' n' b'))) else (cons a (n+n').+1 b') else x else y where "a + b" := (T1add a b) : cantor_scope.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(fintype bigop)