fact: Definition exp_O a b := if (a==zero) then if (b== zero) then one else a else if (a== one) then one else if (T1finite a) then (phi0 b) else phi0 ((T1log a) * T1omega * b).
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(fintype bigop)