Description: Weakening of ax-1 . As a consequence, its associated inference is an instance (where we allow extra hypotheses) of ax-1 . Its commuted form is 2a1 (but ax1w does not require ax-2 ). (Contributed by BJ, 11-Aug-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ax1w | |- ( ph -> ( ps -> ( ch -> ps ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ax-1 | |- ( ps -> ( ch -> ps ) ) |
|
| 2 | 1 | a1i | |- ( ph -> ( ps -> ( ch -> ps ) ) ) |