Description: Define the function giving: the class of all elements of A that are "smaller" than X according to R . (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | df-bnj14 | |- _pred ( X , A , R ) = { y e. A | y R X } |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cX | |- X |
|
1 | cA | |- A |
|
2 | cR | |- R |
|
3 | 1 2 0 | c-bnj14 | |- _pred ( X , A , R ) |
4 | vy | |- y |
|
5 | 4 | cv | |- y |
6 | 5 0 2 | wbr | |- y R X |
7 | 6 4 1 | crab | |- { y e. A | y R X } |
8 | 3 7 | wceq | |- _pred ( X , A , R ) = { y e. A | y R X } |