fact: Definition natmap_partial_alter_raw {A} (f : option A → option A) : nat → natmap_raw A → natmap_raw A := fix go i l {struct l} := match l with | [] => match f None with | Some x => natmap_singleton_raw i x | None => [] end | o :: l => match i with | 0 => natmap_cons_canon (f o) l | S i => natmap_cons_canon o (go i l) end end.
imports: stdpp(fin_maps mapset) stdpp(options)