Description: Apply a choice equivalent. (Contributed by Mario Carneiro, 17-May-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | axaci.1 | ⊢ ( CHOICE ↔ ∀ 𝑥 𝜑 ) | |
| Assertion | axaci | ⊢ 𝜑 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | axaci.1 | ⊢ ( CHOICE ↔ ∀ 𝑥 𝜑 ) | |
| 2 | axac3 | ⊢ CHOICE | |
| 3 | 2 1 | mpbi | ⊢ ∀ 𝑥 𝜑 |
| 4 | 3 | spi | ⊢ 𝜑 |