Description: An equality inference for the proper subclass relationship. (Contributed by NM, 9-Jun-2004)
Ref | Expression | ||
---|---|---|---|
Hypotheses | psseq1i.1 | |
|
psseq12i.2 | |
||
Assertion | psseq12i | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | psseq1i.1 | |
|
2 | psseq12i.2 | |
|
3 | 1 | psseq1i | |
4 | 2 | psseq2i | |
5 | 3 4 | bitri | |