# HG changeset patch # User nipkow # Date 1589492641 -7200 # Node ID f4626b1f1b9689e1bd9531be7fd45587c10473bf # Parent 8ed78bb0b915f6e934a37edbe7ccc1e120dbd39d added lemma diff -r 8ed78bb0b915 -r f4626b1f1b96 src/HOL/Nat.thy --- a/src/HOL/Nat.thy Thu May 14 13:44:44 2020 +0200 +++ b/src/HOL/Nat.thy Thu May 14 23:44:01 2020 +0200 @@ -900,6 +900,9 @@ lemma max_Suc2: "max m (Suc n) = (case m of 0 \ Suc n | Suc m' \ Suc (max m' n))" by (simp split: nat.split) +lemma max_0_iff[simp]: "max m n = (0::nat) \ m = 0 \ n = 0" +by(cases m, auto simp: max_Suc1 split: nat.split) + lemma nat_mult_min_left: "min m n * q = min (m * q) (n * q)" for m n q :: nat by (simp add: min_def not_le)