| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | relxp 5703 | . . . . . . . . 9
⊢ Rel
(𝐴 × 𝐴) | 
| 2 |  | relss 5791 | . . . . . . . . 9
⊢ (𝑅 ⊆ (𝐴 × 𝐴) → (Rel (𝐴 × 𝐴) → Rel 𝑅)) | 
| 3 | 1, 2 | mpi 20 | . . . . . . . 8
⊢ (𝑅 ⊆ (𝐴 × 𝐴) → Rel 𝑅) | 
| 4 | 3 | ad2antlr 727 | . . . . . . 7
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ ¬ 𝐴 ⊆ (dom 𝑅 ∪ ran 𝑅)) → Rel 𝑅) | 
| 5 |  | df-br 5144 | . . . . . . . . . 10
⊢ (𝑥𝑅𝑦 ↔ 〈𝑥, 𝑦〉 ∈ 𝑅) | 
| 6 |  | ssun1 4178 | . . . . . . . . . . . . 13
⊢ 𝐴 ⊆ (𝐴 ∪ {𝑥}) | 
| 7 |  | undif1 4476 | . . . . . . . . . . . . 13
⊢ ((𝐴 ∖ {𝑥}) ∪ {𝑥}) = (𝐴 ∪ {𝑥}) | 
| 8 | 6, 7 | sseqtrri 4033 | . . . . . . . . . . . 12
⊢ 𝐴 ⊆ ((𝐴 ∖ {𝑥}) ∪ {𝑥}) | 
| 9 |  | simpll 767 | . . . . . . . . . . . . . 14
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ 𝑥𝑅𝑦) → 𝑅 Or 𝐴) | 
| 10 |  | dmss 5913 | . . . . . . . . . . . . . . . . 17
⊢ (𝑅 ⊆ (𝐴 × 𝐴) → dom 𝑅 ⊆ dom (𝐴 × 𝐴)) | 
| 11 |  | dmxpid 5941 | . . . . . . . . . . . . . . . . 17
⊢ dom
(𝐴 × 𝐴) = 𝐴 | 
| 12 | 10, 11 | sseqtrdi 4024 | . . . . . . . . . . . . . . . 16
⊢ (𝑅 ⊆ (𝐴 × 𝐴) → dom 𝑅 ⊆ 𝐴) | 
| 13 | 12 | ad2antlr 727 | . . . . . . . . . . . . . . 15
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ 𝑥𝑅𝑦) → dom 𝑅 ⊆ 𝐴) | 
| 14 | 3 | ad2antlr 727 | . . . . . . . . . . . . . . . 16
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ 𝑥𝑅𝑦) → Rel 𝑅) | 
| 15 |  | releldm 5955 | . . . . . . . . . . . . . . . 16
⊢ ((Rel
𝑅 ∧ 𝑥𝑅𝑦) → 𝑥 ∈ dom 𝑅) | 
| 16 | 14, 15 | sylancom 588 | . . . . . . . . . . . . . . 15
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ 𝑥𝑅𝑦) → 𝑥 ∈ dom 𝑅) | 
| 17 | 13, 16 | sseldd 3984 | . . . . . . . . . . . . . 14
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ 𝑥𝑅𝑦) → 𝑥 ∈ 𝐴) | 
| 18 |  | sossfld 6206 | . . . . . . . . . . . . . 14
⊢ ((𝑅 Or 𝐴 ∧ 𝑥 ∈ 𝐴) → (𝐴 ∖ {𝑥}) ⊆ (dom 𝑅 ∪ ran 𝑅)) | 
| 19 | 9, 17, 18 | syl2anc 584 | . . . . . . . . . . . . 13
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ 𝑥𝑅𝑦) → (𝐴 ∖ {𝑥}) ⊆ (dom 𝑅 ∪ ran 𝑅)) | 
| 20 |  | ssun1 4178 | . . . . . . . . . . . . . . 15
⊢ dom 𝑅 ⊆ (dom 𝑅 ∪ ran 𝑅) | 
| 21 | 20, 16 | sselid 3981 | . . . . . . . . . . . . . 14
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ 𝑥𝑅𝑦) → 𝑥 ∈ (dom 𝑅 ∪ ran 𝑅)) | 
| 22 | 21 | snssd 4809 | . . . . . . . . . . . . 13
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ 𝑥𝑅𝑦) → {𝑥} ⊆ (dom 𝑅 ∪ ran 𝑅)) | 
| 23 | 19, 22 | unssd 4192 | . . . . . . . . . . . 12
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ 𝑥𝑅𝑦) → ((𝐴 ∖ {𝑥}) ∪ {𝑥}) ⊆ (dom 𝑅 ∪ ran 𝑅)) | 
| 24 | 8, 23 | sstrid 3995 | . . . . . . . . . . 11
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ 𝑥𝑅𝑦) → 𝐴 ⊆ (dom 𝑅 ∪ ran 𝑅)) | 
| 25 | 24 | ex 412 | . . . . . . . . . 10
⊢ ((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) → (𝑥𝑅𝑦 → 𝐴 ⊆ (dom 𝑅 ∪ ran 𝑅))) | 
| 26 | 5, 25 | biimtrrid 243 | . . . . . . . . 9
⊢ ((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) → (〈𝑥, 𝑦〉 ∈ 𝑅 → 𝐴 ⊆ (dom 𝑅 ∪ ran 𝑅))) | 
| 27 | 26 | con3dimp 408 | . . . . . . . 8
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ ¬ 𝐴 ⊆ (dom 𝑅 ∪ ran 𝑅)) → ¬ 〈𝑥, 𝑦〉 ∈ 𝑅) | 
| 28 | 27 | pm2.21d 121 | . . . . . . 7
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ ¬ 𝐴 ⊆ (dom 𝑅 ∪ ran 𝑅)) → (〈𝑥, 𝑦〉 ∈ 𝑅 → 〈𝑥, 𝑦〉 ∈ ∅)) | 
| 29 | 4, 28 | relssdv 5798 | . . . . . 6
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ ¬ 𝐴 ⊆ (dom 𝑅 ∪ ran 𝑅)) → 𝑅 ⊆ ∅) | 
| 30 |  | ss0 4402 | . . . . . 6
⊢ (𝑅 ⊆ ∅ → 𝑅 = ∅) | 
| 31 | 29, 30 | syl 17 | . . . . 5
⊢ (((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) ∧ ¬ 𝐴 ⊆ (dom 𝑅 ∪ ran 𝑅)) → 𝑅 = ∅) | 
| 32 | 31 | ex 412 | . . . 4
⊢ ((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) → (¬ 𝐴 ⊆ (dom 𝑅 ∪ ran 𝑅) → 𝑅 = ∅)) | 
| 33 | 32 | necon1ad 2957 | . . 3
⊢ ((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴)) → (𝑅 ≠ ∅ → 𝐴 ⊆ (dom 𝑅 ∪ ran 𝑅))) | 
| 34 | 33 | 3impia 1118 | . 2
⊢ ((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴) ∧ 𝑅 ≠ ∅) → 𝐴 ⊆ (dom 𝑅 ∪ ran 𝑅)) | 
| 35 |  | rnss 5950 | . . . . 5
⊢ (𝑅 ⊆ (𝐴 × 𝐴) → ran 𝑅 ⊆ ran (𝐴 × 𝐴)) | 
| 36 |  | rnxpid 6193 | . . . . 5
⊢ ran
(𝐴 × 𝐴) = 𝐴 | 
| 37 | 35, 36 | sseqtrdi 4024 | . . . 4
⊢ (𝑅 ⊆ (𝐴 × 𝐴) → ran 𝑅 ⊆ 𝐴) | 
| 38 | 12, 37 | unssd 4192 | . . 3
⊢ (𝑅 ⊆ (𝐴 × 𝐴) → (dom 𝑅 ∪ ran 𝑅) ⊆ 𝐴) | 
| 39 | 38 | 3ad2ant2 1135 | . 2
⊢ ((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴) ∧ 𝑅 ≠ ∅) → (dom 𝑅 ∪ ran 𝑅) ⊆ 𝐴) | 
| 40 | 34, 39 | eqssd 4001 | 1
⊢ ((𝑅 Or 𝐴 ∧ 𝑅 ⊆ (𝐴 × 𝐴) ∧ 𝑅 ≠ ∅) → 𝐴 = (dom 𝑅 ∪ ran 𝑅)) |