Description: Property of _pred . (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | bnj1418 | |- ( y e. _pred ( x , A , R ) -> y R x ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | breq1 | |- ( z = y -> ( z R x <-> y R x ) ) |
|
2 | df-bnj14 | |- _pred ( x , A , R ) = { z e. A | z R x } |
|
3 | 2 | bnj1538 | |- ( z e. _pred ( x , A , R ) -> z R x ) |
4 | 1 3 | vtoclga | |- ( y e. _pred ( x , A , R ) -> y R x ) |