Proof of Theorem dfac5lem3
| Step | Hyp | Ref
| Expression |
| 1 | | vsnex 5409 |
. . . 4
⊢ {𝑤} ∈ V |
| 2 | | vex 3468 |
. . . 4
⊢ 𝑤 ∈ V |
| 3 | 1, 2 | xpex 7752 |
. . 3
⊢ ({𝑤} × 𝑤) ∈ V |
| 4 | | neeq1 2995 |
. . . 4
⊢ (𝑢 = ({𝑤} × 𝑤) → (𝑢 ≠ ∅ ↔ ({𝑤} × 𝑤) ≠ ∅)) |
| 5 | | eqeq1 2740 |
. . . . 5
⊢ (𝑢 = ({𝑤} × 𝑤) → (𝑢 = ({𝑡} × 𝑡) ↔ ({𝑤} × 𝑤) = ({𝑡} × 𝑡))) |
| 6 | 5 | rexbidv 3165 |
. . . 4
⊢ (𝑢 = ({𝑤} × 𝑤) → (∃𝑡 ∈ ℎ 𝑢 = ({𝑡} × 𝑡) ↔ ∃𝑡 ∈ ℎ ({𝑤} × 𝑤) = ({𝑡} × 𝑡))) |
| 7 | 4, 6 | anbi12d 632 |
. . 3
⊢ (𝑢 = ({𝑤} × 𝑤) → ((𝑢 ≠ ∅ ∧ ∃𝑡 ∈ ℎ 𝑢 = ({𝑡} × 𝑡)) ↔ (({𝑤} × 𝑤) ≠ ∅ ∧ ∃𝑡 ∈ ℎ ({𝑤} × 𝑤) = ({𝑡} × 𝑡)))) |
| 8 | 3, 7 | elab 3663 |
. 2
⊢ (({𝑤} × 𝑤) ∈ {𝑢 ∣ (𝑢 ≠ ∅ ∧ ∃𝑡 ∈ ℎ 𝑢 = ({𝑡} × 𝑡))} ↔ (({𝑤} × 𝑤) ≠ ∅ ∧ ∃𝑡 ∈ ℎ ({𝑤} × 𝑤) = ({𝑡} × 𝑡))) |
| 9 | | dfac5lem.1 |
. . 3
⊢ 𝐴 = {𝑢 ∣ (𝑢 ≠ ∅ ∧ ∃𝑡 ∈ ℎ 𝑢 = ({𝑡} × 𝑡))} |
| 10 | 9 | eleq2i 2827 |
. 2
⊢ (({𝑤} × 𝑤) ∈ 𝐴 ↔ ({𝑤} × 𝑤) ∈ {𝑢 ∣ (𝑢 ≠ ∅ ∧ ∃𝑡 ∈ ℎ 𝑢 = ({𝑡} × 𝑡))}) |
| 11 | | xpeq2 5680 |
. . . . . 6
⊢ (𝑤 = ∅ → ({𝑤} × 𝑤) = ({𝑤} × ∅)) |
| 12 | | xp0 6152 |
. . . . . 6
⊢ ({𝑤} × ∅) =
∅ |
| 13 | 11, 12 | eqtrdi 2787 |
. . . . 5
⊢ (𝑤 = ∅ → ({𝑤} × 𝑤) = ∅) |
| 14 | | rneq 5921 |
. . . . . 6
⊢ (({𝑤} × 𝑤) = ∅ → ran ({𝑤} × 𝑤) = ran ∅) |
| 15 | 2 | snnz 4757 |
. . . . . . 7
⊢ {𝑤} ≠ ∅ |
| 16 | | rnxp 6164 |
. . . . . . 7
⊢ ({𝑤} ≠ ∅ → ran
({𝑤} × 𝑤) = 𝑤) |
| 17 | 15, 16 | ax-mp 5 |
. . . . . 6
⊢ ran
({𝑤} × 𝑤) = 𝑤 |
| 18 | | rn0 5910 |
. . . . . 6
⊢ ran
∅ = ∅ |
| 19 | 14, 17, 18 | 3eqtr3g 2794 |
. . . . 5
⊢ (({𝑤} × 𝑤) = ∅ → 𝑤 = ∅) |
| 20 | 13, 19 | impbii 209 |
. . . 4
⊢ (𝑤 = ∅ ↔ ({𝑤} × 𝑤) = ∅) |
| 21 | 20 | necon3bii 2985 |
. . 3
⊢ (𝑤 ≠ ∅ ↔ ({𝑤} × 𝑤) ≠ ∅) |
| 22 | | df-rex 3062 |
. . . 4
⊢
(∃𝑡 ∈
ℎ ({𝑤} × 𝑤) = ({𝑡} × 𝑡) ↔ ∃𝑡(𝑡 ∈ ℎ ∧ ({𝑤} × 𝑤) = ({𝑡} × 𝑡))) |
| 23 | | rneq 5921 |
. . . . . . . . 9
⊢ (({𝑤} × 𝑤) = ({𝑡} × 𝑡) → ran ({𝑤} × 𝑤) = ran ({𝑡} × 𝑡)) |
| 24 | | vex 3468 |
. . . . . . . . . . 11
⊢ 𝑡 ∈ V |
| 25 | 24 | snnz 4757 |
. . . . . . . . . 10
⊢ {𝑡} ≠ ∅ |
| 26 | | rnxp 6164 |
. . . . . . . . . 10
⊢ ({𝑡} ≠ ∅ → ran
({𝑡} × 𝑡) = 𝑡) |
| 27 | 25, 26 | ax-mp 5 |
. . . . . . . . 9
⊢ ran
({𝑡} × 𝑡) = 𝑡 |
| 28 | 23, 17, 27 | 3eqtr3g 2794 |
. . . . . . . 8
⊢ (({𝑤} × 𝑤) = ({𝑡} × 𝑡) → 𝑤 = 𝑡) |
| 29 | | sneq 4616 |
. . . . . . . . . 10
⊢ (𝑤 = 𝑡 → {𝑤} = {𝑡}) |
| 30 | 29 | xpeq1d 5688 |
. . . . . . . . 9
⊢ (𝑤 = 𝑡 → ({𝑤} × 𝑤) = ({𝑡} × 𝑤)) |
| 31 | | xpeq2 5680 |
. . . . . . . . 9
⊢ (𝑤 = 𝑡 → ({𝑡} × 𝑤) = ({𝑡} × 𝑡)) |
| 32 | 30, 31 | eqtrd 2771 |
. . . . . . . 8
⊢ (𝑤 = 𝑡 → ({𝑤} × 𝑤) = ({𝑡} × 𝑡)) |
| 33 | 28, 32 | impbii 209 |
. . . . . . 7
⊢ (({𝑤} × 𝑤) = ({𝑡} × 𝑡) ↔ 𝑤 = 𝑡) |
| 34 | | equcom 2018 |
. . . . . . 7
⊢ (𝑤 = 𝑡 ↔ 𝑡 = 𝑤) |
| 35 | 33, 34 | bitri 275 |
. . . . . 6
⊢ (({𝑤} × 𝑤) = ({𝑡} × 𝑡) ↔ 𝑡 = 𝑤) |
| 36 | 35 | anbi1ci 626 |
. . . . 5
⊢ ((𝑡 ∈ ℎ ∧ ({𝑤} × 𝑤) = ({𝑡} × 𝑡)) ↔ (𝑡 = 𝑤 ∧ 𝑡 ∈ ℎ)) |
| 37 | 36 | exbii 1848 |
. . . 4
⊢
(∃𝑡(𝑡 ∈ ℎ ∧ ({𝑤} × 𝑤) = ({𝑡} × 𝑡)) ↔ ∃𝑡(𝑡 = 𝑤 ∧ 𝑡 ∈ ℎ)) |
| 38 | | elequ1 2116 |
. . . . 5
⊢ (𝑡 = 𝑤 → (𝑡 ∈ ℎ ↔ 𝑤 ∈ ℎ)) |
| 39 | 38 | equsexvw 2005 |
. . . 4
⊢
(∃𝑡(𝑡 = 𝑤 ∧ 𝑡 ∈ ℎ) ↔ 𝑤 ∈ ℎ) |
| 40 | 22, 37, 39 | 3bitrri 298 |
. . 3
⊢ (𝑤 ∈ ℎ ↔ ∃𝑡 ∈ ℎ ({𝑤} × 𝑤) = ({𝑡} × 𝑡)) |
| 41 | 21, 40 | anbi12i 628 |
. 2
⊢ ((𝑤 ≠ ∅ ∧ 𝑤 ∈ ℎ) ↔ (({𝑤} × 𝑤) ≠ ∅ ∧ ∃𝑡 ∈ ℎ ({𝑤} × 𝑤) = ({𝑡} × 𝑡))) |
| 42 | 8, 10, 41 | 3bitr4i 303 |
1
⊢ (({𝑤} × 𝑤) ∈ 𝐴 ↔ (𝑤 ≠ ∅ ∧ 𝑤 ∈ ℎ)) |