Description: Express "less than or equals" for general strict orders. (Contributed by Stefan O'Rear, 17-Jan-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | poleloe | |- ( B e. V -> ( A ( R u. _I ) B <-> ( A R B \/ A = B ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | brun | |- ( A ( R u. _I ) B <-> ( A R B \/ A _I B ) ) |
|
| 2 | ideqg | |- ( B e. V -> ( A _I B <-> A = B ) ) |
|
| 3 | 2 | orbi2d | |- ( B e. V -> ( ( A R B \/ A _I B ) <-> ( A R B \/ A = B ) ) ) |
| 4 | 1 3 | bitrid | |- ( B e. V -> ( A ( R u. _I ) B <-> ( A R B \/ A = B ) ) ) |