Metamath Proof Explorer


Theorem nnmcli

Description: _om is closed under multiplication. Inference form of nnmcl . (Contributed by Scott Fenton, 20-Apr-2012)

Ref Expression
Hypotheses nncli.1 𝐴 ∈ ω
nncli.2 𝐵 ∈ ω
Assertion nnmcli ( 𝐴 ·o 𝐵 ) ∈ ω

Proof

Step Hyp Ref Expression
1 nncli.1 𝐴 ∈ ω
2 nncli.2 𝐵 ∈ ω
3 nnmcl ( ( 𝐴 ∈ ω ∧ 𝐵 ∈ ω ) → ( 𝐴 ·o 𝐵 ) ∈ ω )
4 1 2 3 mp2an ( 𝐴 ·o 𝐵 ) ∈ ω