Description: Example for df-pw . Example by David A. Wheeler. (Contributed by Mario Carneiro, 2-Jul-2016)
Ref | Expression | ||
---|---|---|---|
Assertion | ex-pw | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pweq | |
|
2 | qdass | |
|
3 | qdassr | |
|
4 | 2 3 | uneq12i | |
5 | pwtp | |
|
6 | df-tp | |
|
7 | 6 | uneq2i | |
8 | unass | |
|
9 | 7 8 | eqtr4i | |
10 | tpass | |
|
11 | 10 | uneq1i | |
12 | 9 11 | eqtr4i | |
13 | unass | |
|
14 | tpass | |
|
15 | 14 | uneq1i | |
16 | df-tp | |
|
17 | 16 | uneq2i | |
18 | 13 15 17 | 3eqtr4i | |
19 | 12 18 | uneq12i | |
20 | un4 | |
|
21 | 19 20 | eqtr4i | |
22 | 4 5 21 | 3eqtr4i | |
23 | 1 22 | eqtrdi | |