author | paulson |
Thu, 02 Nov 2023 14:10:16 +0000 | |
changeset 78882 | c1bd24ca22b6 |
parent 78880 | 9ce8bf038444 (current diff) |
parent 78881 | fb6828831ef1 (diff) |
child 78883 | 5de1c19ccd92 |
--- a/src/HOL/Nat.thy Thu Nov 02 14:31:01 2023 +0100 +++ b/src/HOL/Nat.thy Thu Nov 02 14:10:16 2023 +0000 @@ -342,7 +342,10 @@ lemma Suc_diff_diff [simp]: "(Suc m - n) - Suc k = m - n - k" by (simp add: diff_diff_add) -lemma diff_Suc_1 [simp]: "Suc n - 1 = n" +lemma diff_Suc_1: "Suc n - 1 = n" + by simp + +lemma diff_Suc_1' [simp]: "Suc n - Suc 0 = n" by simp