Description: Membership in an ordered-pair class abstraction defined by a restricted binary relation. (Contributed by AV, 16-Feb-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | elopabran |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpl | ||
2 | 1 | ssopab2i | |
3 | opabss | ||
4 | 2 3 | sstri | |
5 | 4 | sseli |