English
The quotient map commutes with multiplication: Con.toQuotient (x y) = Con.toQuotient x · Con.toQuotient y.
Русский
Коэффициентная карта сохраняет умножение: Con.toQuotient( x y ) = Con.toQuotient x · Con.toQuotient y.
LaTeX
$$$Con.toQuotient (x\\,y) = Con.toQuotient x \\; \\cdot \\; Con.toQuotient y$$$
Lean4
/-- The coercion to the quotient of a congruence relation commutes with multiplication (by
definition). -/
@[to_additive (attr := simp) /-- The coercion to the quotient of an additive congruence relation
commutes with addition (by definition). -/
]
theorem coe_mul (x y : M) : (↑(x * y) : c.Quotient) = ↑x * ↑y :=
rfl