| Step | Hyp | Ref
| Expression |
| 1 | | ssrab2 4060 |
. . . . . 6
⊢ {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋} ⊆ 𝐴 |
| 2 | | sseqin2 4203 |
. . . . . 6
⊢ ({𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋} ⊆ 𝐴 ↔ (𝐴 ∩ {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋}) = {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋}) |
| 3 | 1, 2 | mpbi 230 |
. . . . 5
⊢ (𝐴 ∩ {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋}) = {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋} |
| 4 | | dfrab2 4300 |
. . . . 5
⊢ {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋} = ({𝑦 ∣ 𝑦𝑅𝑋} ∩ 𝐴) |
| 5 | 3, 4 | eqtr2i 2760 |
. . . 4
⊢ ({𝑦 ∣ 𝑦𝑅𝑋} ∩ 𝐴) = (𝐴 ∩ {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋}) |
| 6 | | iniseg 6089 |
. . . . . 6
⊢ (𝑋 ∈ V → (◡𝑅 “ {𝑋}) = {𝑦 ∣ 𝑦𝑅𝑋}) |
| 7 | 6 | ineq2d 4200 |
. . . . 5
⊢ (𝑋 ∈ V → (𝐴 ∩ (◡𝑅 “ {𝑋})) = (𝐴 ∩ {𝑦 ∣ 𝑦𝑅𝑋})) |
| 8 | | incom 4189 |
. . . . 5
⊢ (𝐴 ∩ {𝑦 ∣ 𝑦𝑅𝑋}) = ({𝑦 ∣ 𝑦𝑅𝑋} ∩ 𝐴) |
| 9 | 7, 8 | eqtrdi 2787 |
. . . 4
⊢ (𝑋 ∈ V → (𝐴 ∩ (◡𝑅 “ {𝑋})) = ({𝑦 ∣ 𝑦𝑅𝑋} ∩ 𝐴)) |
| 10 | | iniseg 6089 |
. . . . . 6
⊢ (𝑋 ∈ V → (◡(𝑅 ↾ 𝐴) “ {𝑋}) = {𝑦 ∣ 𝑦(𝑅 ↾ 𝐴)𝑋}) |
| 11 | | brres 5978 |
. . . . . . . 8
⊢ (𝑋 ∈ V → (𝑦(𝑅 ↾ 𝐴)𝑋 ↔ (𝑦 ∈ 𝐴 ∧ 𝑦𝑅𝑋))) |
| 12 | 11 | abbidv 2802 |
. . . . . . 7
⊢ (𝑋 ∈ V → {𝑦 ∣ 𝑦(𝑅 ↾ 𝐴)𝑋} = {𝑦 ∣ (𝑦 ∈ 𝐴 ∧ 𝑦𝑅𝑋)}) |
| 13 | | df-rab 3421 |
. . . . . . 7
⊢ {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋} = {𝑦 ∣ (𝑦 ∈ 𝐴 ∧ 𝑦𝑅𝑋)} |
| 14 | 12, 13 | eqtr4di 2789 |
. . . . . 6
⊢ (𝑋 ∈ V → {𝑦 ∣ 𝑦(𝑅 ↾ 𝐴)𝑋} = {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋}) |
| 15 | 10, 14 | eqtrd 2771 |
. . . . 5
⊢ (𝑋 ∈ V → (◡(𝑅 ↾ 𝐴) “ {𝑋}) = {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋}) |
| 16 | 15 | ineq2d 4200 |
. . . 4
⊢ (𝑋 ∈ V → (𝐴 ∩ (◡(𝑅 ↾ 𝐴) “ {𝑋})) = (𝐴 ∩ {𝑦 ∈ 𝐴 ∣ 𝑦𝑅𝑋})) |
| 17 | 5, 9, 16 | 3eqtr4a 2797 |
. . 3
⊢ (𝑋 ∈ V → (𝐴 ∩ (◡𝑅 “ {𝑋})) = (𝐴 ∩ (◡(𝑅 ↾ 𝐴) “ {𝑋}))) |
| 18 | | df-pred 6295 |
. . 3
⊢
Pred(𝑅, 𝐴, 𝑋) = (𝐴 ∩ (◡𝑅 “ {𝑋})) |
| 19 | | df-pred 6295 |
. . 3
⊢
Pred((𝑅 ↾
𝐴), 𝐴, 𝑋) = (𝐴 ∩ (◡(𝑅 ↾ 𝐴) “ {𝑋})) |
| 20 | 17, 18, 19 | 3eqtr4g 2796 |
. 2
⊢ (𝑋 ∈ V → Pred(𝑅, 𝐴, 𝑋) = Pred((𝑅 ↾ 𝐴), 𝐴, 𝑋)) |
| 21 | | predprc 6332 |
. . 3
⊢ (¬
𝑋 ∈ V →
Pred(𝑅, 𝐴, 𝑋) = ∅) |
| 22 | | predprc 6332 |
. . 3
⊢ (¬
𝑋 ∈ V →
Pred((𝑅 ↾ 𝐴), 𝐴, 𝑋) = ∅) |
| 23 | 21, 22 | eqtr4d 2774 |
. 2
⊢ (¬
𝑋 ∈ V →
Pred(𝑅, 𝐴, 𝑋) = Pred((𝑅 ↾ 𝐴), 𝐴, 𝑋)) |
| 24 | 20, 23 | pm2.61i 182 |
1
⊢
Pred(𝑅, 𝐴, 𝑋) = Pred((𝑅 ↾ 𝐴), 𝐴, 𝑋) |