| Step | Hyp | Ref | Expression |
| 1 |
|
elall2 |
l1, l2 e. all2 R <-> len l1 = len l2 /\ A. n A. x A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. R) |
| 2 |
|
elall2 |
l1, l2 e. all2 S <-> len l1 = len l2 /\ A. n A. x A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. S) |
| 3 |
1, 2 |
imeqi |
l1, l2 e. all2 R -> l1, l2 e. all2 S <->
len l1 = len l2 /\ A. n A. x A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. R) ->
len l1 = len l2 /\ A. n A. x A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. S) |
| 4 |
|
impexp |
x IN l1 /\ y IN l2 -> x, y e. R -> x, y e. S <-> x IN l1 -> y IN l2 -> x, y e. R -> x, y e. S |
| 5 |
|
imim |
(nth n l1 = suc x -> x IN l1) ->
((y IN l2 -> x, y e. R -> x, y e. S) -> (nth n l2 = suc y -> x, y e. R) -> nth n l2 = suc y -> x, y e. S) ->
(x IN l1 -> y IN l2 -> x, y e. R -> x, y e. S) ->
nth n l1 = suc x ->
(nth n l2 = suc y -> x, y e. R) ->
nth n l2 = suc y ->
x, y e. S |
| 6 |
|
nthlmem |
nth n l1 = suc x -> x IN l1 |
| 7 |
5, 6 |
ax_mp |
((y IN l2 -> x, y e. R -> x, y e. S) -> (nth n l2 = suc y -> x, y e. R) -> nth n l2 = suc y -> x, y e. S) ->
(x IN l1 -> y IN l2 -> x, y e. R -> x, y e. S) ->
nth n l1 = suc x ->
(nth n l2 = suc y -> x, y e. R) ->
nth n l2 = suc y ->
x, y e. S |
| 8 |
|
imim1 |
(nth n l2 = suc y -> y IN l2) -> (y IN l2 -> x, y e. R -> x, y e. S) -> nth n l2 = suc y -> x, y e. R -> x, y e. S |
| 9 |
|
nthlmem |
nth n l2 = suc y -> y IN l2 |
| 10 |
8, 9 |
ax_mp |
(y IN l2 -> x, y e. R -> x, y e. S) -> nth n l2 = suc y -> x, y e. R -> x, y e. S |
| 11 |
10 |
a2d |
(y IN l2 -> x, y e. R -> x, y e. S) -> (nth n l2 = suc y -> x, y e. R) -> nth n l2 = suc y -> x, y e. S |
| 12 |
7, 11 |
ax_mp |
(x IN l1 -> y IN l2 -> x, y e. R -> x, y e. S) -> nth n l1 = suc x -> (nth n l2 = suc y -> x, y e. R) -> nth n l2 = suc y -> x, y e. S |
| 13 |
12 |
a2d |
(x IN l1 -> y IN l2 -> x, y e. R -> x, y e. S) -> (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. R) -> nth n l1 = suc x -> nth n l2 = suc y -> x, y e. S |
| 14 |
4, 13 |
sylbi |
(x IN l1 /\ y IN l2 -> x, y e. R -> x, y e. S) -> (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. R) -> nth n l1 = suc x -> nth n l2 = suc y -> x, y e. S |
| 15 |
14 |
al2imi |
A. y (x IN l1 /\ y IN l2 -> x, y e. R -> x, y e. S) ->
A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. R) ->
A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. S) |
| 16 |
15 |
al2imi |
A. x A. y (x IN l1 /\ y IN l2 -> x, y e. R -> x, y e. S) ->
A. x A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. R) ->
A. x A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. S) |
| 17 |
16 |
alimd |
A. x A. y (x IN l1 /\ y IN l2 -> x, y e. R -> x, y e. S) ->
A. n A. x A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. R) ->
A. n A. x A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. S) |
| 18 |
17 |
anim2d |
A. x A. y (x IN l1 /\ y IN l2 -> x, y e. R -> x, y e. S) ->
len l1 = len l2 /\ A. n A. x A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. R) ->
len l1 = len l2 /\ A. n A. x A. y (nth n l1 = suc x -> nth n l2 = suc y -> x, y e. S) |
| 19 |
3, 18 |
sylibr |
A. x A. y (x IN l1 /\ y IN l2 -> x, y e. R -> x, y e. S) -> l1, l2 e. all2 R -> l1, l2 e. all2 S |