Metamath Proof Explorer


Theorem ablcomd

Description: An abelian group operation is commutative, deduction version. (Contributed by Thierry Arnoux, 15-Feb-2026)

Ref Expression
Hypotheses ablcomd.1
|- B = ( Base ` G )
ablcomd.2
|- .+ = ( +g ` G )
ablcomd.3
|- ( ph -> G e. Abel )
ablcomd.4
|- ( ph -> X e. B )
ablcomd.5
|- ( ph -> Y e. B )
Assertion ablcomd
|- ( ph -> ( X .+ Y ) = ( Y .+ X ) )

Proof

Step Hyp Ref Expression
1 ablcomd.1
 |-  B = ( Base ` G )
2 ablcomd.2
 |-  .+ = ( +g ` G )
3 ablcomd.3
 |-  ( ph -> G e. Abel )
4 ablcomd.4
 |-  ( ph -> X e. B )
5 ablcomd.5
 |-  ( ph -> Y e. B )
6 1 2 ablcom
 |-  ( ( G e. Abel /\ X e. B /\ Y e. B ) -> ( X .+ Y ) = ( Y .+ X ) )
7 3 4 5 6 syl3anc
 |-  ( ph -> ( X .+ Y ) = ( Y .+ X ) )