| Step |
Hyp |
Ref |
Expression |
| 1 |
|
disjimeldisjdmqs |
⊢ ( Disj 𝑅 → ElDisj ( dom 𝑅 / 𝑅 ) ) |
| 2 |
|
eldisjsdisj |
⊢ ( 𝑅 ∈ Disjs → ( 𝑅 ∈ Disjs ↔ Disj 𝑅 ) ) |
| 3 |
|
dmqsex |
⊢ ( 𝑅 ∈ Disjs → ( dom 𝑅 / 𝑅 ) ∈ V ) |
| 4 |
|
eleldisjseldisj |
⊢ ( ( dom 𝑅 / 𝑅 ) ∈ V → ( ( dom 𝑅 / 𝑅 ) ∈ ElDisjs ↔ ElDisj ( dom 𝑅 / 𝑅 ) ) ) |
| 5 |
3 4
|
syl |
⊢ ( 𝑅 ∈ Disjs → ( ( dom 𝑅 / 𝑅 ) ∈ ElDisjs ↔ ElDisj ( dom 𝑅 / 𝑅 ) ) ) |
| 6 |
2 5
|
imbi12d |
⊢ ( 𝑅 ∈ Disjs → ( ( 𝑅 ∈ Disjs → ( dom 𝑅 / 𝑅 ) ∈ ElDisjs ) ↔ ( Disj 𝑅 → ElDisj ( dom 𝑅 / 𝑅 ) ) ) ) |
| 7 |
1 6
|
mpbiri |
⊢ ( 𝑅 ∈ Disjs → ( 𝑅 ∈ Disjs → ( dom 𝑅 / 𝑅 ) ∈ ElDisjs ) ) |
| 8 |
7
|
pm2.43i |
⊢ ( 𝑅 ∈ Disjs → ( dom 𝑅 / 𝑅 ) ∈ ElDisjs ) |