intro h
case mpr
X : Type
inst✝¹ : PartialOrder X
inst✝ : CompleteLattice X
x x' : X
⊢ Inf {x, x'} = x → x ≤ x'
case mpr
X : Type
inst✝¹ : PartialOrder X
inst✝ : CompleteLattice X
x x' : X
h : Inf {x, x'} = x
⊢ x ≤ x'