Proof of Theorem pmtrprfv
Step | Hyp | Ref
| Expression |
1 | | simpl 487 |
. . 3
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → 𝐷 ∈ 𝑉) |
2 | | simpr1 1192 |
. . . 4
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → 𝑋 ∈ 𝐷) |
3 | | simpr2 1193 |
. . . 4
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → 𝑌 ∈ 𝐷) |
4 | 2, 3 | prssd 4705 |
. . 3
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → {𝑋, 𝑌} ⊆ 𝐷) |
5 | | pr2nelem 9449 |
. . . 4
⊢ ((𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌) → {𝑋, 𝑌} ≈ 2o) |
6 | 5 | adantl 486 |
. . 3
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → {𝑋, 𝑌} ≈ 2o) |
7 | | pmtrfval.t |
. . . 4
⊢ 𝑇 = (pmTrsp‘𝐷) |
8 | 7 | pmtrfv 18632 |
. . 3
⊢ (((𝐷 ∈ 𝑉 ∧ {𝑋, 𝑌} ⊆ 𝐷 ∧ {𝑋, 𝑌} ≈ 2o) ∧ 𝑋 ∈ 𝐷) → ((𝑇‘{𝑋, 𝑌})‘𝑋) = if(𝑋 ∈ {𝑋, 𝑌}, ∪ ({𝑋, 𝑌} ∖ {𝑋}), 𝑋)) |
9 | 1, 4, 6, 2, 8 | syl31anc 1371 |
. 2
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → ((𝑇‘{𝑋, 𝑌})‘𝑋) = if(𝑋 ∈ {𝑋, 𝑌}, ∪ ({𝑋, 𝑌} ∖ {𝑋}), 𝑋)) |
10 | | prid1g 4646 |
. . . . 5
⊢ (𝑋 ∈ 𝐷 → 𝑋 ∈ {𝑋, 𝑌}) |
11 | 2, 10 | syl 17 |
. . . 4
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → 𝑋 ∈ {𝑋, 𝑌}) |
12 | 11 | iftrued 4421 |
. . 3
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → if(𝑋 ∈ {𝑋, 𝑌}, ∪ ({𝑋, 𝑌} ∖ {𝑋}), 𝑋) = ∪ ({𝑋, 𝑌} ∖ {𝑋})) |
13 | | difprsnss 4682 |
. . . . . . 7
⊢ ({𝑋, 𝑌} ∖ {𝑋}) ⊆ {𝑌} |
14 | 13 | a1i 11 |
. . . . . 6
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → ({𝑋, 𝑌} ∖ {𝑋}) ⊆ {𝑌}) |
15 | | prid2g 4647 |
. . . . . . . . 9
⊢ (𝑌 ∈ 𝐷 → 𝑌 ∈ {𝑋, 𝑌}) |
16 | 3, 15 | syl 17 |
. . . . . . . 8
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → 𝑌 ∈ {𝑋, 𝑌}) |
17 | | simpr3 1194 |
. . . . . . . . 9
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → 𝑋 ≠ 𝑌) |
18 | 17 | necomd 3004 |
. . . . . . . 8
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → 𝑌 ≠ 𝑋) |
19 | | eldifsn 4670 |
. . . . . . . 8
⊢ (𝑌 ∈ ({𝑋, 𝑌} ∖ {𝑋}) ↔ (𝑌 ∈ {𝑋, 𝑌} ∧ 𝑌 ≠ 𝑋)) |
20 | 16, 18, 19 | sylanbrc 587 |
. . . . . . 7
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → 𝑌 ∈ ({𝑋, 𝑌} ∖ {𝑋})) |
21 | 20 | snssd 4692 |
. . . . . 6
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → {𝑌} ⊆ ({𝑋, 𝑌} ∖ {𝑋})) |
22 | 14, 21 | eqssd 3905 |
. . . . 5
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → ({𝑋, 𝑌} ∖ {𝑋}) = {𝑌}) |
23 | 22 | unieqd 4805 |
. . . 4
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → ∪
({𝑋, 𝑌} ∖ {𝑋}) = ∪ {𝑌}) |
24 | | unisng 4812 |
. . . . 5
⊢ (𝑌 ∈ 𝐷 → ∪ {𝑌} = 𝑌) |
25 | 3, 24 | syl 17 |
. . . 4
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → ∪
{𝑌} = 𝑌) |
26 | 23, 25 | eqtrd 2794 |
. . 3
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → ∪
({𝑋, 𝑌} ∖ {𝑋}) = 𝑌) |
27 | 12, 26 | eqtrd 2794 |
. 2
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → if(𝑋 ∈ {𝑋, 𝑌}, ∪ ({𝑋, 𝑌} ∖ {𝑋}), 𝑋) = 𝑌) |
28 | 9, 27 | eqtrd 2794 |
1
⊢ ((𝐷 ∈ 𝑉 ∧ (𝑋 ∈ 𝐷 ∧ 𝑌 ∈ 𝐷 ∧ 𝑋 ≠ 𝑌)) → ((𝑇‘{𝑋, 𝑌})‘𝑋) = 𝑌) |