Description: Indexed intersection with an unordered pair index. (Contributed by NM, 25-Jan-2012)
Ref | Expression | ||
---|---|---|---|
Hypotheses | iinxprg.1 | |
|
iinxprg.2 | |
||
Assertion | iinxprg | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | iinxprg.1 | |
|
2 | iinxprg.2 | |
|
3 | 1 | eleq2d | |
4 | 2 | eleq2d | |
5 | 3 4 | ralprg | |
6 | 5 | abbidv | |
7 | df-iin | |
|
8 | df-in | |
|
9 | 6 7 8 | 3eqtr4g | |