Metamath Proof Explorer


Theorem nmulcomd

Description: Natural multiplication commutes. Deduction form. (Contributed by Scott Fenton, 30-Jul-2026)

Ref Expression
Hypotheses nmul.1
|- ( ph -> A e. On )
nmul.2
|- ( ph -> B e. On )
Assertion nmulcomd
|- ( ph -> ( A .no B ) = ( B .no A ) )

Proof

Step Hyp Ref Expression
1 nmul.1
 |-  ( ph -> A e. On )
2 nmul.2
 |-  ( ph -> B e. On )
3 nmulcom
 |-  ( ( A e. On /\ B e. On ) -> ( A .no B ) = ( B .no A ) )
4 1 2 3 syl2anc
 |-  ( ph -> ( A .no B ) = ( B .no A ) )