Description: The Godel-set version of the Axiom of Extensionality. (Contributed by Mario Carneiro, 14-Jul-2013)
Ref | Expression | ||
---|---|---|---|
Assertion | df-gzext | |- AxExt = ( A.g 2o ( ( 2o e.g (/) ) <->g ( 2o e.g 1o ) ) ->g ( (/) =g 1o ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cgze | |- AxExt |
|
1 | c2o | |- 2o |
|
2 | cgoe | |- e.g |
|
3 | c0 | |- (/) |
|
4 | 1 3 2 | co | |- ( 2o e.g (/) ) |
5 | cgob | |- <->g |
|
6 | c1o | |- 1o |
|
7 | 1 6 2 | co | |- ( 2o e.g 1o ) |
8 | 4 7 5 | co | |- ( ( 2o e.g (/) ) <->g ( 2o e.g 1o ) ) |
9 | 8 1 | cgol | |- A.g 2o ( ( 2o e.g (/) ) <->g ( 2o e.g 1o ) ) |
10 | cgoi | |- ->g |
|
11 | cgoq | |- =g |
|
12 | 3 6 11 | co | |- ( (/) =g 1o ) |
13 | 9 12 10 | co | |- ( A.g 2o ( ( 2o e.g (/) ) <->g ( 2o e.g 1o ) ) ->g ( (/) =g 1o ) ) |
14 | 0 13 | wceq | |- AxExt = ( A.g 2o ( ( 2o e.g (/) ) <->g ( 2o e.g 1o ) ) ->g ( (/) =g 1o ) ) |