Reference · Natural numbers
rainbow.math.nat.multiply-zero-split
nat/multiply-zero-split : a*b = 0 -> (a = 0) or (b = 0). Nested Nat.rec: a=0 gives the left disjunct; a=succ p with b=0 gives the right disjunct; a=succ p, b=succ q makes (succ p)*(succ q) a successor, so =0 is refuted. The general nat no-zero-divisors -- foundation for the general nnrat/signed no-zero-divisors that strict convexity needs (generalizes nat/square-zero-implies-zero).
nat/multiply-zero-split
nat/multiply-zero-split : (a b : ℕ) (h : nat/multiply a b = 0) → proposition/disjunction (a = 0) (b = 0)
= = equality/Eqℕ = data/Nat