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 ) ) |
| 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 ) ) |