Description: "At most one" double quantification. Usage of this theorem is discouraged because it depends on ax-13 . Use the weaker moexexvw when possible. (Contributed by NM, 26-Jan-1997) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | moexexv | |- ( ( E* x ph /\ A. x E* y ps ) -> E* y E. x ( ph /\ ps ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | nfv | |- F/ y ph | |
| 2 | 1 | moexex | |- ( ( E* x ph /\ A. x E* y ps ) -> E* y E. x ( ph /\ ps ) ) |