English
For a NonAssocSemiring α, @[simp] theorem nsmul_eq_mul: n • a = n * a for all n ∈ ℕ, a ∈ α.
Русский
Для неассоциированной полугруппы α, @[simp] теорема nsmul_eq_mul: n • a = n * a для всех n ∈ ℕ, a ∈ α.
LaTeX
$$$ n \cdot a = n \cdot a $$$
Lean4
instance (priority := 100) negZeroClass : NegZeroClass α
where
__ := inferInstanceAs (Zero α); __ := inferInstanceAs (InvolutiveNeg α)
neg_zero := by rw [← zero_mul (0 : α), ← neg_mul, mul_zero, mul_zero]