Step | Hyp | Ref
| Expression |
1 | | fveq2 6881 |
. . . 4
⊢ (𝐴 = ⟨𝑥, 𝑦, 𝑧⟩ → (2nd ‘𝐴) = (2nd
‘⟨𝑥, 𝑦, 𝑧⟩)) |
2 | | ot3rdg 7984 |
. . . . 5
⊢ (𝑧 ∈ V → (2nd
‘⟨𝑥, 𝑦, 𝑧⟩) = 𝑧) |
3 | 2 | elv 3472 |
. . . 4
⊢
(2nd ‘⟨𝑥, 𝑦, 𝑧⟩) = 𝑧 |
4 | 1, 3 | eqtr2di 2781 |
. . 3
⊢ (𝐴 = ⟨𝑥, 𝑦, 𝑧⟩ → 𝑧 = (2nd ‘𝐴)) |
5 | | sbceq1a 3780 |
. . 3
⊢ (𝑧 = (2nd ‘𝐴) → (𝜑 ↔ [(2nd ‘𝐴) / 𝑧]𝜑)) |
6 | 4, 5 | syl 17 |
. 2
⊢ (𝐴 = ⟨𝑥, 𝑦, 𝑧⟩ → (𝜑 ↔ [(2nd ‘𝐴) / 𝑧]𝜑)) |
7 | | 2fveq3 6886 |
. . . 4
⊢ (𝐴 = ⟨𝑥, 𝑦, 𝑧⟩ → (2nd
‘(1st ‘𝐴)) = (2nd ‘(1st
‘⟨𝑥, 𝑦, 𝑧⟩))) |
8 | | vex 3470 |
. . . . 5
⊢ 𝑥 ∈ V |
9 | | vex 3470 |
. . . . 5
⊢ 𝑦 ∈ V |
10 | | vex 3470 |
. . . . 5
⊢ 𝑧 ∈ V |
11 | | ot2ndg 7983 |
. . . . 5
⊢ ((𝑥 ∈ V ∧ 𝑦 ∈ V ∧ 𝑧 ∈ V) →
(2nd ‘(1st ‘⟨𝑥, 𝑦, 𝑧⟩)) = 𝑦) |
12 | 8, 9, 10, 11 | mp3an 1457 |
. . . 4
⊢
(2nd ‘(1st ‘⟨𝑥, 𝑦, 𝑧⟩)) = 𝑦 |
13 | 7, 12 | eqtr2di 2781 |
. . 3
⊢ (𝐴 = ⟨𝑥, 𝑦, 𝑧⟩ → 𝑦 = (2nd ‘(1st
‘𝐴))) |
14 | | sbceq1a 3780 |
. . 3
⊢ (𝑦 = (2nd
‘(1st ‘𝐴)) → ([(2nd
‘𝐴) / 𝑧]𝜑 ↔ [(2nd
‘(1st ‘𝐴)) / 𝑦][(2nd ‘𝐴) / 𝑧]𝜑)) |
15 | 13, 14 | syl 17 |
. 2
⊢ (𝐴 = ⟨𝑥, 𝑦, 𝑧⟩ → ([(2nd
‘𝐴) / 𝑧]𝜑 ↔ [(2nd
‘(1st ‘𝐴)) / 𝑦][(2nd ‘𝐴) / 𝑧]𝜑)) |
16 | | 2fveq3 6886 |
. . . 4
⊢ (𝐴 = ⟨𝑥, 𝑦, 𝑧⟩ → (1st
‘(1st ‘𝐴)) = (1st ‘(1st
‘⟨𝑥, 𝑦, 𝑧⟩))) |
17 | | ot1stg 7982 |
. . . . 5
⊢ ((𝑥 ∈ V ∧ 𝑦 ∈ V ∧ 𝑧 ∈ V) →
(1st ‘(1st ‘⟨𝑥, 𝑦, 𝑧⟩)) = 𝑥) |
18 | 8, 9, 10, 17 | mp3an 1457 |
. . . 4
⊢
(1st ‘(1st ‘⟨𝑥, 𝑦, 𝑧⟩)) = 𝑥 |
19 | 16, 18 | eqtr2di 2781 |
. . 3
⊢ (𝐴 = ⟨𝑥, 𝑦, 𝑧⟩ → 𝑥 = (1st ‘(1st
‘𝐴))) |
20 | | sbceq1a 3780 |
. . 3
⊢ (𝑥 = (1st
‘(1st ‘𝐴)) → ([(2nd
‘(1st ‘𝐴)) / 𝑦][(2nd ‘𝐴) / 𝑧]𝜑 ↔ [(1st
‘(1st ‘𝐴)) / 𝑥][(2nd
‘(1st ‘𝐴)) / 𝑦][(2nd ‘𝐴) / 𝑧]𝜑)) |
21 | 19, 20 | syl 17 |
. 2
⊢ (𝐴 = ⟨𝑥, 𝑦, 𝑧⟩ → ([(2nd
‘(1st ‘𝐴)) / 𝑦][(2nd ‘𝐴) / 𝑧]𝜑 ↔ [(1st
‘(1st ‘𝐴)) / 𝑥][(2nd
‘(1st ‘𝐴)) / 𝑦][(2nd ‘𝐴) / 𝑧]𝜑)) |
22 | 6, 15, 21 | 3bitrrd 306 |
1
⊢ (𝐴 = ⟨𝑥, 𝑦, 𝑧⟩ → ([(1st
‘(1st ‘𝐴)) / 𝑥][(2nd
‘(1st ‘𝐴)) / 𝑦][(2nd ‘𝐴) / 𝑧]𝜑 ↔ 𝜑)) |