English
The symmetric application of prodEquivOfIsCompl to a pair maps back to a sum representation with the left component 0 or right component 0 depending on the side; i.e., symmetry yields (0, x) or (x, 0) accordingly.
Русский
Симметрическое применение prodEquivOfIsCompl к паре восстанавливает сумму: либо (0, x), либо (x, 0) в зависимости от стороны.
LaTeX
$$$(prodEquivOfIsCompl p q h).symm x = (0, x)$ or $(x, 0)$$$
Lean4
@[simp]
theorem coe_prodEquivOfIsCompl' (h : IsCompl p q) (x : p × q) : prodEquivOfIsCompl p q h x = x.1 + x.2 :=
rfl