Description: Elementhood of a preimage. (Contributed by Thierry Arnoux, 21-Jan-2017)
Ref | Expression | ||
---|---|---|---|
Hypotheses | orvcval.1 | |
|
orvcval.2 | |
||
orvcval.3 | |
||
Assertion | elorvc | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | orvcval.1 | |
|
2 | orvcval.2 | |
|
3 | orvcval.3 | |
|
4 | 1 2 3 | orvcval2 | |
5 | 4 | eleq2d | |
6 | rabid | |
|
7 | 5 6 | bitrdi | |
8 | 7 | baibd | |