Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | bnj596.1 | |- ( ph -> A. x ph ) |
|
| bnj596.2 | |- ( ph -> E. x ps ) |
||
| Assertion | bnj596 | |- ( ph -> E. x ( ph /\ ps ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | bnj596.1 | |- ( ph -> A. x ph ) |
|
| 2 | bnj596.2 | |- ( ph -> E. x ps ) |
|
| 3 | 2 | ancli | |- ( ph -> ( ph /\ E. x ps ) ) |
| 4 | 1 | nf5i | |- F/ x ph |
| 5 | 4 | 19.42 | |- ( E. x ( ph /\ ps ) <-> ( ph /\ E. x ps ) ) |
| 6 | 3 5 | sylibr | |- ( ph -> E. x ( ph /\ ps ) ) |