Description: Existential quantification restricted to a subclass. (Contributed by NM, 11-Jan-2007) Avoid axioms. (Revised by GG, 19-May-2025)
Ref | Expression | ||
---|---|---|---|
Assertion | ssrexv |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-ss | ||
2 | pm3.45 | ||
3 | 2 | aleximi | |
4 | df-rex | ||
5 | df-rex | ||
6 | 3 4 5 | 3imtr4g | |
7 | 1 6 | sylbi |