Description: If G is a global choice function, then the Axiom of Choice holds. This is gblacfnacd expressed using CHOICE . (Contributed by BTernaryTau, 25-Sep-2026)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | gblacfnac2d.1 | |- ( ph -> G Fn _V ) |
|
| gblacfnac2d.2 | |- ( ph -> A. z ( z =/= (/) -> ( G ` z ) e. z ) ) |
||
| Assertion | gblacfnac2d | |- ( ph -> CHOICE ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | gblacfnac2d.1 | |- ( ph -> G Fn _V ) |
|
| 2 | gblacfnac2d.2 | |- ( ph -> A. z ( z =/= (/) -> ( G ` z ) e. z ) ) |
|
| 3 | 1 2 | gblacfnacd | |- ( ph -> A. x E. f ( f Fn x /\ A. z e. x ( z =/= (/) -> ( f ` z ) e. z ) ) ) |
| 4 | dfac4 | |- ( CHOICE <-> A. x E. f ( f Fn x /\ A. z e. x ( z =/= (/) -> ( f ` z ) e. z ) ) ) |
|
| 5 | 3 4 | sylibr | |- ( ph -> CHOICE ) |