| Step | Hyp | Ref | Expression |
| 1 |
|
bitr |
(p e. Compl (Xp _V A) <-> ~p e. Xp _V A) -> (~p e. Xp _V A <-> p e. Xp _V (Compl A)) -> (p e. Compl (Xp _V A) <-> p e. Xp _V (Compl A)) |
| 2 |
|
elcpl |
p e. Compl (Xp _V A) <-> ~p e. Xp _V A |
| 3 |
1, 2 |
ax_mp |
(~p e. Xp _V A <-> p e. Xp _V (Compl A)) -> (p e. Compl (Xp _V A) <-> p e. Xp _V (Compl A)) |
| 4 |
|
bitr4 |
(~p e. Xp _V A <-> ~snd p e. A) -> (p e. Xp _V (Compl A) <-> ~snd p e. A) -> (~p e. Xp _V A <-> p e. Xp _V (Compl A)) |
| 5 |
|
noteq |
(p e. Xp _V A <-> snd p e. A) -> (~p e. Xp _V A <-> ~snd p e. A) |
| 6 |
|
bitr |
(p e. Xp _V A <-> fst p e. _V /\ snd p e. A) -> (fst p e. _V /\ snd p e. A <-> snd p e. A) -> (p e. Xp _V A <-> snd p e. A) |
| 7 |
|
elxp |
p e. Xp _V A <-> fst p e. _V /\ snd p e. A |
| 8 |
6, 7 |
ax_mp |
(fst p e. _V /\ snd p e. A <-> snd p e. A) -> (p e. Xp _V A <-> snd p e. A) |
| 9 |
|
bian1 |
fst p e. _V -> (fst p e. _V /\ snd p e. A <-> snd p e. A) |
| 10 |
|
elv |
fst p e. _V |
| 11 |
9, 10 |
ax_mp |
fst p e. _V /\ snd p e. A <-> snd p e. A |
| 12 |
8, 11 |
ax_mp |
p e. Xp _V A <-> snd p e. A |
| 13 |
5, 12 |
ax_mp |
~p e. Xp _V A <-> ~snd p e. A |
| 14 |
4, 13 |
ax_mp |
(p e. Xp _V (Compl A) <-> ~snd p e. A) -> (~p e. Xp _V A <-> p e. Xp _V (Compl A)) |
| 15 |
|
bitr |
(p e. Xp _V (Compl A) <-> fst p e. _V /\ snd p e. Compl A) -> (fst p e. _V /\ snd p e. Compl A <-> ~snd p e. A) -> (p e. Xp _V (Compl A) <-> ~snd p e. A) |
| 16 |
|
elxp |
p e. Xp _V (Compl A) <-> fst p e. _V /\ snd p e. Compl A |
| 17 |
15, 16 |
ax_mp |
(fst p e. _V /\ snd p e. Compl A <-> ~snd p e. A) -> (p e. Xp _V (Compl A) <-> ~snd p e. A) |
| 18 |
|
bitr |
(fst p e. _V /\ snd p e. Compl A <-> snd p e. Compl A) -> (snd p e. Compl A <-> ~snd p e. A) -> (fst p e. _V /\ snd p e. Compl A <-> ~snd p e. A) |
| 19 |
|
bian1 |
fst p e. _V -> (fst p e. _V /\ snd p e. Compl A <-> snd p e. Compl A) |
| 20 |
19, 10 |
ax_mp |
fst p e. _V /\ snd p e. Compl A <-> snd p e. Compl A |
| 21 |
18, 20 |
ax_mp |
(snd p e. Compl A <-> ~snd p e. A) -> (fst p e. _V /\ snd p e. Compl A <-> ~snd p e. A) |
| 22 |
|
elcpl |
snd p e. Compl A <-> ~snd p e. A |
| 23 |
21, 22 |
ax_mp |
fst p e. _V /\ snd p e. Compl A <-> ~snd p e. A |
| 24 |
17, 23 |
ax_mp |
p e. Xp _V (Compl A) <-> ~snd p e. A |
| 25 |
14, 24 |
ax_mp |
~p e. Xp _V A <-> p e. Xp _V (Compl A) |
| 26 |
3, 25 |
ax_mp |
p e. Compl (Xp _V A) <-> p e. Xp _V (Compl A) |
| 27 |
26 |
eqri |
Compl (Xp _V A) == Xp _V (Compl A) |