fact: Definition Pick := \big[Or/False]_(p : {ffun pred I}) ((\big[And/True]_i (if p i then pred_f i else ~ pred_f i)) /\ (if pick p is Some i then then_f i else else_f))%qfT.
imports: mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq choice fintype) mathcomp(finfun path matrix) mathcomp(bigop order ssralg poly polydiv ssrnum zmodp div ssrint) mathcomp(polyorder polyrcf interval polyXY) mathcomp(qe_rcf_th ordered_qelim mxtens)