Description: Rederivation of ax-c5 from axc5c711 . Only propositional calculus is used by the rederivation. (Contributed by NM, 19-Nov-2006) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | axc5c711toc5 | |- ( A. x ph -> ph ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ax-1 | |- ( A. x ph -> ( A. x A. x -. A. x A. x ph -> A. x ph ) ) |
|
| 2 | axc5c711 | |- ( ( A. x A. x -. A. x A. x ph -> A. x ph ) -> ph ) |
|
| 3 | 1 2 | syl | |- ( A. x ph -> ph ) |