Description: Condition for an operation to be one-to-one. (Contributed by Jeff Madsen, 17-Jun-2010)
Ref | Expression | ||
---|---|---|---|
Assertion | f1opr | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dff13 | |
|
2 | fveq2 | |
|
3 | df-ov | |
|
4 | 2 3 | eqtr4di | |
5 | 4 | eqeq1d | |
6 | eqeq1 | |
|
7 | 5 6 | imbi12d | |
8 | 7 | ralbidv | |
9 | 8 | ralxp | |
10 | fveq2 | |
|
11 | df-ov | |
|
12 | 10 11 | eqtr4di | |
13 | 12 | eqeq2d | |
14 | eqeq2 | |
|
15 | vex | |
|
16 | vex | |
|
17 | 15 16 | opth | |
18 | 14 17 | bitrdi | |
19 | 13 18 | imbi12d | |
20 | 19 | ralxp | |
21 | 20 | 2ralbii | |
22 | 9 21 | bitri | |
23 | 22 | anbi2i | |
24 | 1 23 | bitri | |