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 ∈ 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 ∈ 𝐴 ∣ 𝑦 𝑅 𝑋 } |
8 | 3 7 | wceq | ⊢ pred ( 𝑋 , 𝐴 , 𝑅 ) = { 𝑦 ∈ 𝐴 ∣ 𝑦 𝑅 𝑋 } |