Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypothesis | bnj941.1 | |
|
Assertion | bnj941 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | bnj941.1 | |
|
2 | opeq2 | |
|
3 | 2 | sneqd | |
4 | 3 | uneq2d | |
5 | 1 4 | eqtrid | |
6 | 5 | fneq1d | |
7 | 6 | imbi2d | |
8 | eqid | |
|
9 | 0ex | |
|
10 | 9 | elimel | |
11 | 8 10 | bnj927 | |
12 | 7 11 | dedth | |