Description: Existential quantification over a class abstraction. (Contributed by Mario Carneiro, 23-Jan-2014) (Revised by Mario Carneiro, 3-Sep-2015) Reduce axiom usage. (Revised by Gino Giotto, 2-Nov-2024)
Ref | Expression | ||
---|---|---|---|
Hypothesis | ralab.1 | |
|
Assertion | rexab | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ralab.1 | |
|
2 | dfrex2 | |
|
3 | 1 | ralab | |
4 | 2 3 | xchbinx | |
5 | imnang | |
|
6 | 4 5 | xchbinx | |
7 | df-ex | |
|
8 | 6 7 | bitr4i | |