fact: Definition is_first_char_such_that (might_be_empty : Prop) (str : String) (n : nat) P := forall_chars (take n str) (fun ch => ~P ch) /\ ((for_first_char (drop n str) P /\ n < length str) \/ (might_be_empty /\ length str <= n)).
imports: Fiat.Common.Coq__8_4__8_5__Compat Coq.Arith.PeanoNat Fiat.Parsers.StringLike.Core Fiat.Parsers.StringLike.Properties Fiat.Parsers.StringLike.ForallChars Fiat.Parsers.StringLike.FirstChar Fiat.Common Fiat.Common.NatFacts