Detailed syntax breakdown of Definition df-se
| Step | Hyp | Ref
| Expression |
| 1 | | cA |
. . 3
class 𝐴 |
| 2 | | cR |
. . 3
class 𝑅 |
| 3 | 1, 2 | wse 4365 |
. 2
wff 𝑅 Se 𝐴 |
| 4 | | vy |
. . . . . . 7
setvar 𝑦 |
| 5 | 4 | cv 1363 |
. . . . . 6
class 𝑦 |
| 6 | | vx |
. . . . . . 7
setvar 𝑥 |
| 7 | 6 | cv 1363 |
. . . . . 6
class 𝑥 |
| 8 | 5, 7, 2 | wbr 4034 |
. . . . 5
wff 𝑦𝑅𝑥 |
| 9 | 8, 4, 1 | crab 2479 |
. . . 4
class {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑥} |
| 10 | | cvv 2763 |
. . . 4
class
V |
| 11 | 9, 10 | wcel 2167 |
. . 3
wff {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑥} ∈ V |
| 12 | 11, 6, 1 | wral 2475 |
. 2
wff
∀𝑥 ∈
𝐴 {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑥} ∈ V |
| 13 | 3, 12 | wb 105 |
1
wff (𝑅 Se 𝐴 ↔ ∀𝑥 ∈ 𝐴 {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑥} ∈ V) |