Description: Subset theorem for transposition. (Contributed by Mario Carneiro, 10-Sep-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | tposss | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | coss1 | |
|
2 | dmss | |
|
3 | cnvss | |
|
4 | unss1 | |
|
5 | resmpt | |
|
6 | 2 3 4 5 | 4syl | |
7 | resss | |
|
8 | 6 7 | eqsstrrdi | |
9 | coss2 | |
|
10 | 8 9 | syl | |
11 | 1 10 | sstrd | |
12 | df-tpos | |
|
13 | df-tpos | |
|
14 | 11 12 13 | 3sstr4g | |