Description: Alternate proof of bj-ssbid2 , not using sbequ2 . (Contributed by BJ, 22-Dec-2020) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | bj-ssbid2ALT | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-sb | |
|
2 | sp | |
|
3 | 2 | imim2i | |
4 | 3 | alimi | |
5 | pm2.21 | |
|
6 | equcomi | |
|
7 | 6 | imim1i | |
8 | 5 7 | ja | |
9 | 8 | alimi | |
10 | ax6ev | |
|
11 | 19.23v | |
|
12 | 11 | biimpi | |
13 | 9 10 12 | mpisyl | |
14 | 4 13 | syl | |
15 | 1 14 | sylbi | |