Description: Ordering relation for the cumulative hierarchy of sets. Part of Theorem 3.3(i) of BellMachover p. 478. (Contributed by NM, 22-Sep-2003)
Ref | Expression | ||
---|---|---|---|
Assertion | r1ord3 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | r1fnon | ||
2 | fndm | ||
3 | 1 2 | ax-mp | |
4 | 3 | eleq2i | |
5 | 3 | eleq2i | |
6 | r1ord3g | ||
7 | 4 5 6 | syl2anbr |