Metamath Proof Explorer


Theorem nnmsuc

Description: Multiplication with successor. Theorem 4J(A2) of Enderton p. 80. (Contributed by NM, 20-Sep-1995) (Revised by Mario Carneiro, 14-Nov-2014)

Ref Expression
Assertion nnmsuc ( ( 𝐴 ∈ ω ∧ 𝐵 ∈ ω ) → ( 𝐴 ·o suc 𝐵 ) = ( ( 𝐴 ·o 𝐵 ) +o 𝐴 ) )

Proof

Step Hyp Ref Expression
1 nnon ( 𝐴 ∈ ω → 𝐴 ∈ On )
2 onmsuc ( ( 𝐴 ∈ On ∧ 𝐵 ∈ ω ) → ( 𝐴 ·o suc 𝐵 ) = ( ( 𝐴 ·o 𝐵 ) +o 𝐴 ) )
3 1 2 sylan ( ( 𝐴 ∈ ω ∧ 𝐵 ∈ ω ) → ( 𝐴 ·o suc 𝐵 ) = ( ( 𝐴 ·o 𝐵 ) +o 𝐴 ) )