lemma
proved
wrapper
extendMask_notin
show as:
view Lean formalization →
formal statement (Lean)
39@[simp] lemma extendMask_notin (M : Finset (Fin n)) (a : {i // i ∈ M} → Bool) {i : Fin n} (h : i ∉ M) :
40 extendMask (n:=n) M a i = false := by
proof body
One-line wrapper that applies simp.
41 simp [extendMask, h]
42