Step |
Hyp |
Ref |
Expression |
1 |
|
mpoxeldm.f |
⊢ 𝐹 = ( 𝑥 ∈ 𝐶 , 𝑦 ∈ 𝐷 ↦ 𝑅 ) |
2 |
|
df-nel |
⊢ ( 𝑋 ∉ 𝐶 ↔ ¬ 𝑋 ∈ 𝐶 ) |
3 |
|
df-nel |
⊢ ( 𝑌 ∉ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ↔ ¬ 𝑌 ∈ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) |
4 |
2 3
|
orbi12i |
⊢ ( ( 𝑋 ∉ 𝐶 ∨ 𝑌 ∉ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) ↔ ( ¬ 𝑋 ∈ 𝐶 ∨ ¬ 𝑌 ∈ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) ) |
5 |
|
ianor |
⊢ ( ¬ ( 𝑋 ∈ 𝐶 ∧ 𝑌 ∈ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) ↔ ( ¬ 𝑋 ∈ 𝐶 ∨ ¬ 𝑌 ∈ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) ) |
6 |
4 5
|
bitr4i |
⊢ ( ( 𝑋 ∉ 𝐶 ∨ 𝑌 ∉ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) ↔ ¬ ( 𝑋 ∈ 𝐶 ∧ 𝑌 ∈ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) ) |
7 |
|
neq0 |
⊢ ( ¬ ( 𝑋 𝐹 𝑌 ) = ∅ ↔ ∃ 𝑛 𝑛 ∈ ( 𝑋 𝐹 𝑌 ) ) |
8 |
1
|
mpoxeldm |
⊢ ( 𝑛 ∈ ( 𝑋 𝐹 𝑌 ) → ( 𝑋 ∈ 𝐶 ∧ 𝑌 ∈ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) ) |
9 |
8
|
exlimiv |
⊢ ( ∃ 𝑛 𝑛 ∈ ( 𝑋 𝐹 𝑌 ) → ( 𝑋 ∈ 𝐶 ∧ 𝑌 ∈ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) ) |
10 |
7 9
|
sylbi |
⊢ ( ¬ ( 𝑋 𝐹 𝑌 ) = ∅ → ( 𝑋 ∈ 𝐶 ∧ 𝑌 ∈ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) ) |
11 |
10
|
con1i |
⊢ ( ¬ ( 𝑋 ∈ 𝐶 ∧ 𝑌 ∈ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) → ( 𝑋 𝐹 𝑌 ) = ∅ ) |
12 |
6 11
|
sylbi |
⊢ ( ( 𝑋 ∉ 𝐶 ∨ 𝑌 ∉ ⦋ 𝑋 / 𝑥 ⦌ 𝐷 ) → ( 𝑋 𝐹 𝑌 ) = ∅ ) |