Theorem: N.mul_one (LeanTeaching/TD/TD02_sol.lean)

State before:
S : Type
image_zero : S
image_succ : N → S → S
a b c : N
⊢ a * 1 = a
Tactic:
rw [one_eq_succ_zero, mul_succ, mul_zero, zero_add]
State after:
no goals