English
A top submodule on the N-side is determined by the IsPerfectCompl condition with the top submodule; specifically, p.IsPerfectCompl ⊤ V iff V = ⊤.
Русский
Условие IsPerfectCompl для верхнего подмодуля слева задаёт топ-подмодуль; p.IsPerfectCompl ⊤ V эквивалентно V = ⊤.
LaTeX
$$$p.IsPerfectCompl \\top V \\iff V = \\top$.$$
Lean4
@[simp]
theorem left_top_iff : p.IsPerfectCompl ⊤ V ↔ V = ⊤ :=
by
refine ⟨fun h ↦ ?_, fun h ↦ ?_⟩
· exact eq_top_of_isCompl_bot <| by simpa using h.isCompl_right
· rw [h]
exact
{ isCompl_left := by simpa using isCompl_top_bot
isCompl_right := by simpa using isCompl_top_bot }