Proof of Theorem 2wlkdlem6
| Step | Hyp | Ref
| Expression |
| 1 | | 2wlkd.e |
. 2
⊢ (𝜑 → ({𝐴, 𝐵} ⊆ (𝐼‘𝐽) ∧ {𝐵, 𝐶} ⊆ (𝐼‘𝐾))) |
| 2 | | prcom 4671 |
. . . . . . . 8
⊢ {𝐴, 𝐵} = {𝐵, 𝐴} |
| 3 | 2 | sseq1i 3950 |
. . . . . . 7
⊢ ({𝐴, 𝐵} ⊆ (𝐼‘𝐽) ↔ {𝐵, 𝐴} ⊆ (𝐼‘𝐽)) |
| 4 | 3 | bilani 505 |
. . . . . 6
⊢ ((𝜑 ∧ {𝐴, 𝐵} ⊆ (𝐼‘𝐽)) → {𝐵, 𝐴} ⊆ (𝐼‘𝐽)) |
| 5 | | 2wlkd.s |
. . . . . . . 8
⊢ (𝜑 → (𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉)) |
| 6 | 5 | simp2d 1149 |
. . . . . . 7
⊢ (𝜑 → 𝐵 ∈ 𝑉) |
| 7 | 5 | simp1d 1148 |
. . . . . . . 8
⊢ (𝜑 → 𝐴 ∈ 𝑉) |
| 8 | 7 | adantr 481 |
. . . . . . 7
⊢ ((𝜑 ∧ {𝐴, 𝐵} ⊆ (𝐼‘𝐽)) → 𝐴 ∈ 𝑉) |
| 9 | | prssg 4757 |
. . . . . . 7
⊢ ((𝐵 ∈ 𝑉 ∧ 𝐴 ∈ 𝑉) → ((𝐵 ∈ (𝐼‘𝐽) ∧ 𝐴 ∈ (𝐼‘𝐽)) ↔ {𝐵, 𝐴} ⊆ (𝐼‘𝐽))) |
| 10 | 6, 8, 9 | syl2an2r 691 |
. . . . . 6
⊢ ((𝜑 ∧ {𝐴, 𝐵} ⊆ (𝐼‘𝐽)) → ((𝐵 ∈ (𝐼‘𝐽) ∧ 𝐴 ∈ (𝐼‘𝐽)) ↔ {𝐵, 𝐴} ⊆ (𝐼‘𝐽))) |
| 11 | 4, 10 | mpbird 258 |
. . . . 5
⊢ ((𝜑 ∧ {𝐴, 𝐵} ⊆ (𝐼‘𝐽)) → (𝐵 ∈ (𝐼‘𝐽) ∧ 𝐴 ∈ (𝐼‘𝐽))) |
| 12 | 11 | simpld 495 |
. . . 4
⊢ ((𝜑 ∧ {𝐴, 𝐵} ⊆ (𝐼‘𝐽)) → 𝐵 ∈ (𝐼‘𝐽)) |
| 13 | 12 | ex 413 |
. . 3
⊢ (𝜑 → ({𝐴, 𝐵} ⊆ (𝐼‘𝐽) → 𝐵 ∈ (𝐼‘𝐽))) |
| 14 | | simpr 485 |
. . . . . 6
⊢ ((𝜑 ∧ {𝐵, 𝐶} ⊆ (𝐼‘𝐾)) → {𝐵, 𝐶} ⊆ (𝐼‘𝐾)) |
| 15 | 5 | simp3d 1150 |
. . . . . . . 8
⊢ (𝜑 → 𝐶 ∈ 𝑉) |
| 16 | 15 | adantr 481 |
. . . . . . 7
⊢ ((𝜑 ∧ {𝐵, 𝐶} ⊆ (𝐼‘𝐾)) → 𝐶 ∈ 𝑉) |
| 17 | | prssg 4757 |
. . . . . . 7
⊢ ((𝐵 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) → ((𝐵 ∈ (𝐼‘𝐾) ∧ 𝐶 ∈ (𝐼‘𝐾)) ↔ {𝐵, 𝐶} ⊆ (𝐼‘𝐾))) |
| 18 | 6, 16, 17 | syl2an2r 691 |
. . . . . 6
⊢ ((𝜑 ∧ {𝐵, 𝐶} ⊆ (𝐼‘𝐾)) → ((𝐵 ∈ (𝐼‘𝐾) ∧ 𝐶 ∈ (𝐼‘𝐾)) ↔ {𝐵, 𝐶} ⊆ (𝐼‘𝐾))) |
| 19 | 14, 18 | mpbird 258 |
. . . . 5
⊢ ((𝜑 ∧ {𝐵, 𝐶} ⊆ (𝐼‘𝐾)) → (𝐵 ∈ (𝐼‘𝐾) ∧ 𝐶 ∈ (𝐼‘𝐾))) |
| 20 | 19 | simpld 495 |
. . . 4
⊢ ((𝜑 ∧ {𝐵, 𝐶} ⊆ (𝐼‘𝐾)) → 𝐵 ∈ (𝐼‘𝐾)) |
| 21 | 20 | ex 413 |
. . 3
⊢ (𝜑 → ({𝐵, 𝐶} ⊆ (𝐼‘𝐾) → 𝐵 ∈ (𝐼‘𝐾))) |
| 22 | 13, 21 | anim12d 615 |
. 2
⊢ (𝜑 → (({𝐴, 𝐵} ⊆ (𝐼‘𝐽) ∧ {𝐵, 𝐶} ⊆ (𝐼‘𝐾)) → (𝐵 ∈ (𝐼‘𝐽) ∧ 𝐵 ∈ (𝐼‘𝐾)))) |
| 23 | 1, 22 | mpd 15 |
1
⊢ (𝜑 → (𝐵 ∈ (𝐼‘𝐽) ∧ 𝐵 ∈ (𝐼‘𝐾))) |