English
The termination of map f s is equivalent to the termination of s: Terminates (map f s) ↔ Terminates s.
Русский
Завершение отображения map f s эквивалентно завершению s: Terminates (map f s) ⇔ Terminates s.
LaTeX
$$$\operatorname{Terminates}\big(\operatorname{map} f\, s\big) \iff \operatorname{Terminates}(s)$$$
Lean4
theorem terminates_map_iff (f : α → β) (s : Computation α) : Terminates (map f s) ↔ Terminates s :=
⟨fun ⟨⟨_, h⟩⟩ =>
let ⟨_, h1, _⟩ := exists_of_mem_map h
⟨⟨_, h1⟩⟩,
@Computation.terminates_map _ _ _ _⟩
-- Parallel computation