| Step | Hyp | Ref
 | Expression | 
| 1 |   | eleq1 2413 | 
. . . . 5
⊢ (w = v →
(w ∈
S ↔ v ∈ S)) | 
| 2 |   | oveq2 5532 | 
. . . . . 6
⊢ (w = v →
(AFw) = (AFv)) | 
| 3 | 2 | eqeq1d 2361 | 
. . . . 5
⊢ (w = v →
((AFw) = B ↔ (AFv) = B)) | 
| 4 | 1, 3 | anbi12d 691 | 
. . . 4
⊢ (w = v →
((w ∈
S ∧
(AFw) = B) ↔ (v
∈ S ∧ (AFv) = B))) | 
| 5 | 4 | mo4 2237 | 
. . 3
⊢ (∃*w(w ∈ S ∧ (AFw) = B) ↔
∀w∀v(((w ∈ S ∧ (AFw) = B) ∧ (v ∈ S ∧ (AFv) = B)) → w =
v)) | 
| 6 |   | caovmo.1 | 
. . . . . . . . 9
⊢ A ∈
V | 
| 7 |   | vex 2863 | 
. . . . . . . . 9
⊢ w ∈
V | 
| 8 |   | vex 2863 | 
. . . . . . . . 9
⊢ v ∈
V | 
| 9 |   | caovmo.ass | 
. . . . . . . . 9
⊢ ((xFy)Fz) = (xF(yFz)) | 
| 10 | 6, 7, 8, 9 | caovass 5628 | 
. . . . . . . 8
⊢ ((AFw)Fv) = (AF(wFv)) | 
| 11 |   | caovmo.com | 
. . . . . . . . 9
⊢ (xFy) = (yFx) | 
| 12 | 6, 7, 8, 11, 9 | caov12 5637 | 
. . . . . . . 8
⊢ (AF(wFv)) = (wF(AFv)) | 
| 13 | 10, 12 | eqtri 2373 | 
. . . . . . 7
⊢ ((AFw)Fv) = (wF(AFv)) | 
| 14 |   | oveq2 5532 | 
. . . . . . . 8
⊢ ((AFv) = B →
(wF(AFv)) = (wFB)) | 
| 15 |   | oveq1 5531 | 
. . . . . . . . . 10
⊢ (x = w →
(xFB) = (wFB)) | 
| 16 |   | id 19 | 
. . . . . . . . . 10
⊢ (x = w →
x = w) | 
| 17 | 15, 16 | eqeq12d 2367 | 
. . . . . . . . 9
⊢ (x = w →
((xFB) = x ↔ (wFB) = w)) | 
| 18 |   | caovmo.id | 
. . . . . . . . 9
⊢ (x ∈ S → (xFB) = x) | 
| 19 | 17, 18 | vtoclga 2921 | 
. . . . . . . 8
⊢ (w ∈ S → (wFB) = w) | 
| 20 | 14, 19 | sylan9eqr 2407 | 
. . . . . . 7
⊢ ((w ∈ S ∧ (AFv) = B) →
(wF(AFv)) = w) | 
| 21 | 13, 20 | syl5eq 2397 | 
. . . . . 6
⊢ ((w ∈ S ∧ (AFv) = B) →
((AFw)Fv) = w) | 
| 22 | 21 | ad2ant2rl 729 | 
. . . . 5
⊢ (((w ∈ S ∧ (AFw) = B) ∧ (v ∈ S ∧ (AFv) = B)) → ((AFw)Fv) = w) | 
| 23 |   | oveq1 5531 | 
. . . . . . 7
⊢ ((AFw) = B →
((AFw)Fv) = (BFv)) | 
| 24 |   | caovmo.2 | 
. . . . . . . . . 10
⊢ B ∈ S | 
| 25 | 24 | elexi 2869 | 
. . . . . . . . 9
⊢ B ∈
V | 
| 26 | 25, 8, 11 | caovcom 5626 | 
. . . . . . . 8
⊢ (BFv) = (vFB) | 
| 27 |   | oveq1 5531 | 
. . . . . . . . . 10
⊢ (x = v →
(xFB) = (vFB)) | 
| 28 |   | id 19 | 
. . . . . . . . . 10
⊢ (x = v →
x = v) | 
| 29 | 27, 28 | eqeq12d 2367 | 
. . . . . . . . 9
⊢ (x = v →
((xFB) = x ↔ (vFB) = v)) | 
| 30 | 29, 18 | vtoclga 2921 | 
. . . . . . . 8
⊢ (v ∈ S → (vFB) = v) | 
| 31 | 26, 30 | syl5eq 2397 | 
. . . . . . 7
⊢ (v ∈ S → (BFv) = v) | 
| 32 | 23, 31 | sylan9eq 2405 | 
. . . . . 6
⊢ (((AFw) = B ∧ v ∈ S) →
((AFw)Fv) = v) | 
| 33 | 32 | ad2ant2lr 728 | 
. . . . 5
⊢ (((w ∈ S ∧ (AFw) = B) ∧ (v ∈ S ∧ (AFv) = B)) → ((AFw)Fv) = v) | 
| 34 | 22, 33 | eqtr3d 2387 | 
. . . 4
⊢ (((w ∈ S ∧ (AFw) = B) ∧ (v ∈ S ∧ (AFv) = B)) → w =
v) | 
| 35 | 34 | ax-gen 1546 | 
. . 3
⊢ ∀v(((w ∈ S ∧ (AFw) = B) ∧ (v ∈ S ∧ (AFv) = B)) → w =
v) | 
| 36 | 5, 35 | mpgbir 1550 | 
. 2
⊢ ∃*w(w ∈ S ∧ (AFw) = B) | 
| 37 |   | eleq1 2413 | 
. . . . . 6
⊢ ((AFw) = B →
((AFw) ∈ S ↔
B ∈
S)) | 
| 38 | 24, 37 | mpbiri 224 | 
. . . . 5
⊢ ((AFw) = B →
(AFw) ∈ S) | 
| 39 |   | caovmo.dom | 
. . . . . . 7
⊢ dom F = (S ×
S) | 
| 40 |   | caovmo.3 | 
. . . . . . 7
⊢  ¬ ∅ ∈ S | 
| 41 | 7, 39, 40 | ndmovrcl 5617 | 
. . . . . 6
⊢ ((AFw) ∈ S → (A
∈ S ∧ w ∈ S)) | 
| 42 | 41 | simprd 449 | 
. . . . 5
⊢ ((AFw) ∈ S → w ∈ S) | 
| 43 | 38, 42 | syl 15 | 
. . . 4
⊢ ((AFw) = B →
w ∈
S) | 
| 44 | 43 | ancri 535 | 
. . 3
⊢ ((AFw) = B →
(w ∈
S ∧
(AFw) = B)) | 
| 45 | 44 | moimi 2251 | 
. 2
⊢ (∃*w(w ∈ S ∧ (AFw) = B) →
∃*w(AFw) = B) | 
| 46 | 36, 45 | ax-mp 5 | 
1
⊢ ∃*w(AFw) = B |