Proof of Theorem poss
| Step | Hyp | Ref
| Expression |
| 1 | | ssel 1502 |
. . . . . . . . . 10
⊢ (A
⊆ B → (x ∈ A
→ x ∈ B)) |
| 2 | | ssel 1502 |
. . . . . . . . . 10
⊢ (A
⊆ B → (y ∈ A
→ y ∈ B)) |
| 3 | 1, 2 | anim12d 431 |
. . . . . . . . 9
⊢ (A
⊆ B → ((x ∈ A ∧
y ∈ A) → (x
∈ B ∧ y ∈ B))) |
| 4 | | ssel 1502 |
. . . . . . . . 9
⊢ (A
⊆ B → (z ∈ A
→ z ∈ B)) |
| 5 | 3, 4 | anim12d 431 |
. . . . . . . 8
⊢ (A
⊆ B → (((x ∈ A ∧
y ∈ A) ∧ z
∈ A) → ((x ∈ B ∧
y ∈ B) ∧ z
∈ B))) |
| 6 | | df-3an 583 |
. . . . . . . 8
⊢ ((x
∈ A ∧ y ∈ A ∧
z ∈ A) ↔ ((x
∈ A ∧ y ∈ A)
∧ z ∈ A)) |
| 7 | | df-3an 583 |
. . . . . . . 8
⊢ ((x
∈ B ∧ y ∈ B ∧
z ∈ B) ↔ ((x
∈ B ∧ y ∈ B)
∧ z ∈ B)) |
| 8 | 5, 6, 7 | 3imtr4g 426 |
. . . . . . 7
⊢ (A
⊆ B → ((x ∈ A ∧
y ∈ A ∧ z ∈
A) → (x ∈ B ∧
y ∈ B ∧ z ∈
B))) |
| 9 | 8 | syl4d 28 |
. . . . . 6
⊢ (A
⊆ B → (((x ∈ B ∧
y ∈ B ∧ z ∈
B) → (¬ xRx ∧ ((xRy ∧ yRz) → xRz))) → ((x
∈ A ∧ y ∈ A ∧
z ∈ A) → (¬ xRx ∧ ((xRy ∧ yRz) → xRz))))) |
| 10 | 9 | 19.20dv 946 |
. . . . 5
⊢ (A
⊆ B → (∀z((x ∈
B ∧ y ∈ B ∧
z ∈ B) → (¬ xRx ∧ ((xRy ∧ yRz) → xRz))) → ∀z((x ∈
A ∧ y ∈ A ∧
z ∈ A) → (¬ xRx ∧ ((xRy ∧ yRz) → xRz))))) |
| 11 | 10 | 19.20dv 946 |
. . . 4
⊢ (A
⊆ B → (∀y∀z((x ∈
B ∧ y ∈ B ∧
z ∈ B) → (¬ xRx ∧ ((xRy ∧ yRz) → xRz))) → ∀y∀z((x ∈
A ∧ y ∈ A ∧
z ∈ A) → (¬ xRx ∧ ((xRy ∧ yRz) → xRz))))) |
| 12 | 11 | 19.20dv 946 |
. . 3
⊢ (A
⊆ B → (∀x∀y∀z((x ∈
B ∧ y ∈ B ∧
z ∈ B) → (¬ xRx ∧ ((xRy ∧ yRz) → xRz))) → ∀x∀y∀z((x ∈
A ∧ y ∈ A ∧
z ∈ A) → (¬ xRx ∧ ((xRy ∧ yRz) → xRz))))) |
| 13 | | r3al 1240 |
. . 3
⊢ (∀x ∈ B
∀y ∈ B ∀z
∈ B (¬ xRx ∧ ((xRy ∧ yRz) → xRz)) ↔ ∀x∀y∀z((x ∈
B ∧ y ∈ B ∧
z ∈ B) → (¬ xRx ∧ ((xRy ∧ yRz) → xRz)))) |
| 14 | | r3al 1240 |
. . 3
⊢ (∀x ∈ A
∀y ∈ A ∀z
∈ A (¬ xRx ∧ ((xRy ∧ yRz) → xRz)) ↔ ∀x∀y∀z((x ∈
A ∧ y ∈ A ∧
z ∈ A) → (¬ xRx ∧ ((xRy ∧ yRz) → xRz)))) |
| 15 | 12, 13, 14 | 3imtr4g 426 |
. 2
⊢ (A
⊆ B → (∀x ∈ B
∀y ∈ B ∀z
∈ B (¬ xRx ∧ ((xRy ∧ yRz) → xRz)) → ∀x ∈ A
∀y ∈ A ∀z
∈ A (¬ xRx ∧ ((xRy ∧ yRz) → xRz)))) |
| 16 | | df-po 2128 |
. 2
⊢ (R Po
B ↔ ∀x ∈ B
∀y ∈ B ∀z
∈ B (¬ xRx ∧ ((xRy ∧ yRz) → xRz))) |
| 17 | | df-po 2128 |
. 2
⊢ (R Po
A ↔ ∀x ∈ A
∀y ∈ A ∀z
∈ A (¬ xRx ∧ ((xRy ∧ yRz) → xRz))) |
| 18 | 15, 16, 17 | 3imtr4g 426 |
1
⊢ (A
⊆ B → (R Po B →
R Po A)) |