fact: Definition forall_chars (str : String) (P : Char -> Prop) := forall n ch, take 1 (drop n str) ~= [ ch ] -> P ch.
imports: Fiat.Common.Coq__8_4__8_5__Compat Coq.ZArith.ZArith Fiat.Parsers.StringLike.Core Fiat.Parsers.StringLike.Properties Fiat.Common