fact: Fixpoint list_seq_except start len except := match len with | 0%nat => [] | S len' => match except with | [] => [start … list_seq_except (S start) len' []] | [x … l] => if eq_nat_dec start x then list_seq_except (S start) len' l else [start … list_seq_except (S start) len' except] end end.
imports: Utf8 Arith NPeano Sorted Misc