English
Mate equivalence commutes with vertical composition of squares.
Русский
Эквивалентность мейт сохраняет вертикальное композиционное квадрат.
LaTeX
$$$$(\\text{mateEquiv adj1 adj3})\\big(\\alpha \\; \\vcomp\\; \\beta\\big) = (\\text{mateEquiv adj1 adj2 }\\alpha) \\; \\vcomp \\; (\\text{mateEquiv adj2 adj3 }\\beta).$$$$
Lean4
/-- A component of a transposed version of the inverse mates correspondence. -/
theorem mateEquiv_counit_symm (α : TwoSquare R₁ H G R₂) (d : D) :
L₂.map (α.app _) ≫ adj₂.counit.app _ = ((mateEquiv adj₁ adj₂).symm α).app _ ≫ H.map (adj₁.counit.app d) :=
by
conv_lhs => rw [← (mateEquiv adj₁ adj₂).right_inv α]
exact
(mateEquiv_counit adj₁ adj₂ ((mateEquiv adj₁ adj₂).symm α) d)
/- A component of a transposed version of the mates correspondence. -/