English
The determinant-type identity holds: gcdW(a,b) * gcdZ(a,b) equals succPNat of gcdX(a,b) * gcdY(a,b).
Русский
Сохраняется идентичность типа детерминанта: gcdW(a,b) · gcdZ(a,b) = succPNat( gcdX(a,b) · gcdY(a,b) ).
LaTeX
$$$\gcdW(a,b) \cdot gcdZ(a,b) = \operatorname{succPNat}(gcdX(a,b) \cdot gcdY(a,b))$$$
Lean4
theorem gcd_det_eq : gcdW a b * gcdZ a b = succPNat (gcdX a b * gcdY a b) :=
(gcd_props a b).1