English
If P implies Q for all x, then Minimal (P ∧ Q) x is equivalent to Minimal P x and Q x.
Русский
Если для всех x из P следует Q, тогда Minimal (P ∧ Q) x эквивалентно (Minimal P x) и Q x.
LaTeX
$$$\\bigl(\\forall x, P(x) \\to Q(x)\\bigr) \\to \\text{Minimal}(x \\mapsto P(x) \\land Q(x))\\, x \\iff (\\text{Minimal } P\\, x) \\land Q x$$$
Lean4
theorem minimal_and_iff_right_of_imp (hPQ : ∀ ⦃x⦄, P x → Q x) : Minimal (fun x ↦ P x ∧ Q x) x ↔ (Minimal P x) ∧ Q x :=
by
simp_rw [and_iff_left_of_imp (fun x ↦ hPQ x), iff_self_and]
exact fun h ↦ hPQ h.prop