English
The map snd: M × N → N is a monoid homomorphism projecting onto the second coordinate.
Русский
Отображение snd: M × N → N является однородной гомоморфизмом, проекцией на вторую координату.
LaTeX
$$$(\text{snd})( (m,n)\cdot (m',n') ) = (\text{snd}(m,n))\cdot (\text{snd}(m',n'))$$$
Lean4
/-- Given magmas `M`, `N`, the natural projection homomorphism from `M × N` to `N`. -/
@[to_additive /-- Given additive magmas `A`, `B`, the natural projection homomorphism
from `A × B` to `B` -/
]
def snd : M × N →ₙ* N :=
⟨Prod.snd, fun _ _ => rfl⟩