Description: Ordinal less than is equivalent to having an ordinal between them. (Contributed by Scott Fenton, 8-Aug-2024)
Ref | Expression | ||
---|---|---|---|
Assertion | onelssex |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ssid | ||
2 | sseq2 | ||
3 | 2 | rspcev | |
4 | 1 3 | mpan2 | |
5 | ontr2 | ||
6 | 5 | expcomd | |
7 | 6 | rexlimdv | |
8 | 4 7 | impbid2 |