Proof of Theorem grpinvf
| Step | Hyp | Ref
| Expression |
| 1 | | rnexg 3365 |
. . . . . . . . . 10
⊢ (G ∈ Grp → ran
G ∈
V) |
| 2 | | grpasscan1.1 |
. . . . . . . . . 10
⊢ X = ran G |
| 3 | 1, 2 | syl5eqel 1555 |
. . . . . . . . 9
⊢ (G ∈ Grp →
X ∈
V) |
| 4 | | rabexg 2729 |
. . . . . . . . 9
⊢ (X ∈ V
→ {z ∈ X∣(zGx) = (Id
‘G)} ∈ V) |
| 5 | 3, 4 | syl 10 |
. . . . . . . 8
⊢ (G ∈ Grp →
{z ∈
X∣(zGx) = (Id
‘G)} ∈ V) |
| 6 | | uniexg 2877 |
. . . . . . . 8
⊢ ({z ∈ X∣(zGx) = (Id ‘G)} ∈ V
→ ∪{z ∈ X∣(zGx) = (Id
‘G)} ∈ V) |
| 7 | 5, 6 | syl 10 |
. . . . . . 7
⊢ (G ∈ Grp →
∪{z ∈ X∣(zGx) = (Id
‘G)} ∈ V) |
| 8 | 7 | adantr 391 |
. . . . . 6
⊢ ((G ∈ Grp ⋀ x ∈ X) →
∪{z ∈ X∣(zGx) = (Id
‘G)} ∈ V) |
| 9 | 8 | r19.21aiva 1717 |
. . . . 5
⊢ (G ∈ Grp →
∀x
∈ X ∪{z ∈ X∣(zGx) = (Id
‘G)} ∈ V) |
| 10 | | eqid 1478 |
. . . . . 6
⊢ {〈x, y〉∣(x ∈ X ⋀ y = ∪{z ∈ X∣(zGx) = (Id
‘G)})} = {〈x, y〉∣(x ∈ X ⋀ y = ∪{z ∈ X∣(zGx) = (Id
‘G)})} |
| 11 | 10 | fnopab2g 3622 |
. . . . 5
⊢ (∀x ∈ X ∪{z ∈ X∣(zGx) = (Id
‘G)} ∈ V ↔ {〈x, y〉∣(x ∈ X ⋀ y = ∪{z ∈ X∣(zGx) = (Id
‘G)})} Fn X) |
| 12 | 9, 11 | sylib 198 |
. . . 4
⊢ (G ∈ Grp →
{〈x,
y〉∣(x ∈ X ⋀ y = ∪{z ∈ X∣(zGx) = (Id
‘G)})} Fn X) |
| 13 | | eqid 1478 |
. . . . . 6
⊢ (Id ‘G) = (Id ‘G) |
| 14 | | grpasscan1.2 |
. . . . . 6
⊢ N = (inv ‘G) |
| 15 | 2, 13, 14 | grpinvfval 8062 |
. . . . 5
⊢ (G ∈ Grp →
N = {〈x, y〉∣(x ∈ X ⋀ y = ∪{z ∈ X∣(zGx) = (Id
‘G)})}) |
| 16 | | fneq1 3588 |
. . . . 5
⊢ (N = {〈x, y〉∣(x ∈ X ⋀ y = ∪{z ∈ X∣(zGx) = (Id ‘G)})} → (N
Fn X ↔ {〈x, y〉∣(x ∈ X ⋀ y = ∪{z ∈ X∣(zGx) = (Id
‘G)})} Fn X)) |
| 17 | 15, 16 | syl 10 |
. . . 4
⊢ (G ∈ Grp →
(N Fn X
↔ {〈x, y〉∣(x ∈ X ⋀ y = ∪{z ∈ X∣(zGx) = (Id ‘G)})} Fn X)) |
| 18 | 12, 17 | mpbird 196 |
. . 3
⊢ (G ∈ Grp →
N Fn X) |
| 19 | | fnrnfv 3765 |
. . . . 5
⊢ (N Fn X →
ran N = {y∣∃x ∈ X y = (N
‘x)}) |
| 20 | 18, 19 | syl 10 |
. . . 4
⊢ (G ∈ Grp → ran
N = {y∣∃x ∈ X y = (N
‘x)}) |
| 21 | | fveq2 3730 |
. . . . . . . . . 10
⊢ (x = (N
‘y) → (N ‘x) =
(N ‘(N ‘y))) |
| 22 | 21 | eqeq2d 1489 |
. . . . . . . . 9
⊢ (x = (N
‘y) → (y = (N
‘x) ↔ y = (N
‘(N ‘y)))) |
| 23 | 22 | rcla4ev 1880 |
. . . . . . . 8
⊢ (((N ‘y)
∈ X ⋀ y =
(N ‘(N ‘y)))
→ ∃x ∈ X y = (N ‘x)) |
| 24 | 2, 14 | grpinvcl 8064 |
. . . . . . . 8
⊢ ((G ∈ Grp ⋀ y ∈ X) →
(N ‘y) ∈ X) |
| 25 | 2, 14 | grp2inv 8074 |
. . . . . . . . 9
⊢ ((G ∈ Grp ⋀ y ∈ X) →
(N ‘(N ‘y)) =
y) |
| 26 | 25 | eqcomd 1483 |
. . . . . . . 8
⊢ ((G ∈ Grp ⋀ y ∈ X) →
y = (N
‘(N ‘y))) |
| 27 | 23, 24, 26 | sylanc 473 |
. . . . . . 7
⊢ ((G ∈ Grp ⋀ y ∈ X) →
∃x ∈ X y = (N
‘x)) |
| 28 | 27 | ex 373 |
. . . . . 6
⊢ (G ∈ Grp →
(y ∈
X → ∃x ∈ X y = (N
‘x))) |
| 29 | | pm3.27 323 |
. . . . . . . . 9
⊢ (((G ∈ Grp ⋀ x ∈ X) ⋀ y =
(N ‘x)) → y =
(N ‘x)) |
| 30 | 2, 14 | grpinvcl 8064 |
. . . . . . . . . 10
⊢ ((G ∈ Grp ⋀ x ∈ X) →
(N ‘x) ∈ X) |
| 31 | 30 | adantr 391 |
. . . . . . . . 9
⊢ (((G ∈ Grp ⋀ x ∈ X) ⋀ y =
(N ‘x)) → (N
‘x) ∈ X) |
| 32 | 29, 31 | eqeltrd 1551 |
. . . . . . . 8
⊢ (((G ∈ Grp ⋀ x ∈ X) ⋀ y =
(N ‘x)) → y
∈ X) |
| 33 | 32 | exp31 378 |
. . . . . . 7
⊢ (G ∈ Grp →
(x ∈
X → (y = (N
‘x) → y ∈ X))) |
| 34 | 33 | r19.23adv 1749 |
. . . . . 6
⊢ (G ∈ Grp →
(∃x
∈ X
y = (N
‘x) → y ∈ X)) |
| 35 | 28, 34 | impbid 518 |
. . . . 5
⊢ (G ∈ Grp →
(y ∈
X ↔ ∃x ∈ X y = (N
‘x))) |
| 36 | 35 | abbi2dv 1581 |
. . . 4
⊢ (G ∈ Grp →
X = {y∣∃x ∈ X y = (N
‘x)}) |
| 37 | 20, 36 | eqtr4d 1513 |
. . 3
⊢ (G ∈ Grp → ran
N = X) |
| 38 | 2, 14 | grp2inv 8074 |
. . . . . . . 8
⊢ ((G ∈ Grp ⋀ x ∈ X) →
(N ‘(N ‘x)) =
x) |
| 39 | 38, 25 | eqeqan12d 1493 |
. . . . . . 7
⊢ (((G ∈ Grp ⋀ x ∈ X) ⋀ (G ∈ Grp ⋀ y ∈ X)) → ((N
‘(N ‘x)) = (N
‘(N ‘y)) ↔ x =
y)) |
| 40 | 39 | anandis 514 |
. . . . . 6
⊢ ((G ∈ Grp ⋀ (x ∈ X ⋀ y ∈ X)) →
((N ‘(N ‘x)) =
(N ‘(N ‘y))
↔ x = y)) |
| 41 | | fveq2 3730 |
. . . . . 6
⊢ ((N ‘x) =
(N ‘y) → (N
‘(N ‘x)) = (N
‘(N ‘y))) |
| 42 | 40, 41 | syl5bi 208 |
. . . . 5
⊢ ((G ∈ Grp ⋀ (x ∈ X ⋀ y ∈ X)) →
((N ‘x) = (N
‘y) → x = y)) |
| 43 | 42 | ex 373 |
. . . 4
⊢ (G ∈ Grp →
((x ∈
X ⋀
y ∈
X) → ((N ‘x) =
(N ‘y) → x =
y))) |
| 44 | 43 | r19.21aivv 1723 |
. . 3
⊢ (G ∈ Grp →
∀x
∈ X ∀y ∈ X ((N ‘x) =
(N ‘y) → x =
y)) |
| 45 | 18, 37, 44 | 3jca 821 |
. 2
⊢ (G ∈ Grp →
(N Fn X
⋀ ran N
= X ⋀
∀x
∈ X ∀y ∈ X ((N ‘x) =
(N ‘y) → x =
y))) |
| 46 | | f1ofv 3883 |
. 2
⊢ (N:X–1-1-onto→X ↔
(N Fn X
⋀ ran N
= X ⋀
∀x
∈ X ∀y ∈ X ((N ‘x) =
(N ‘y) → x =
y))) |
| 47 | 45, 46 | sylibr 200 |
1
⊢ (G ∈ Grp →
N:X–1-1-onto→X) |