1:: | |- (. A. x x = y ->. A. x x = y ).
|
2:: | |- (. A. x x = y ,. x = u ->. x = u ).
|
3:1: | |- (. A. x x = y ->. x = y ).
|
4:2,3: | |- (. A. x x = y ,. x = u ->. y = u ).
|
5:2,4: | |- (. A. x x = y ,. x = u ->. ( x = u /\ y
= u ) ).
|
6:5: | |- (. A. x x = y ->. ( x = u -> ( x = u /\
y = u ) ) ).
|
7:6: | |- ( A. x x = y -> ( x = u -> ( x = u /\ y
= u ) ) )
|
8:7: | |- ( A. x A. x x = y -> A. x ( x = u -> (
x = u /\ y = u ) ) )
|
9:: | |- ( A. x x = y <-> A. x A. x x = y )
|
10:8,9: | |- ( A. x x = y -> A. x ( x = u -> ( x = u
/\ y = u ) ) )
|
11:1,10: | |- (. A. x x = y ->. A. x ( x = u -> ( x =
u /\ y = u ) ) ).
|
12:11: | |- (. A. x x = y ->. ( E. x x = u -> E. x
( x = u /\ y = u ) ) ).
|
13:: | |- E. x x = u
|
14:13,12: | |- (. A. x x = y ->. E. x ( x = u /\ y = u
) ).
|
140:14: | |- ( A. x x = y -> E. x ( x = u /\ y = u )
)
|
141:140: | |- ( A. x x = y -> A. x E. x ( x = u /\ y
= u ) )
|
15:1,141: | |- (. A. x x = y ->. A. x E. x ( x = u /\
y = u ) ).
|
16:1,15: | |- (. A. x x = y ->. A. y E. x ( x = u /\
y = u ) ).
|
17:16: | |- (. A. x x = y ->. E. y E. x ( x = u /\
y = u ) ).
|
18:17: | |- (. A. x x = y ->. E. x E. y ( x = u /\
y = u ) ).
|
19:: | |- (. u = v ->. u = v ).
|
20:: | |- (. u = v ,. ( x = u /\ y = u ) ->. ( x =
u /\ y = u ) ).
|
21:20: | |- (. u = v ,. ( x = u /\ y = u ) ->. y = u
).
|
22:19,21: | |- (. u = v ,. ( x = u /\ y = u ) ->. y = v
).
|
23:20: | |- (. u = v ,. ( x = u /\ y = u ) ->. x = u
).
|
24:22,23: | |- (. u = v ,. ( x = u /\ y = u ) ->. ( x =
u /\ y = v ) ).
|
25:24: | |- (. u = v ->. ( ( x = u /\ y = u ) -> (
x = u /\ y = v ) ) ).
|
26:25: | |- (. u = v ->. A. y ( ( x = u /\ y = u )
-> ( x = u /\ y = v ) ) ).
|
27:26: | |- (. u = v ->. ( E. y ( x = u /\ y = u )
-> E. y ( x = u /\ y = v ) ) ).
|
28:27: | |- (. u = v ->. A. x ( E. y ( x = u /\ y =
u ) -> E. y ( x = u /\ y = v ) ) ).
|
29:28: | |- (. u = v ->. ( E. x E. y ( x = u /\ y =
u ) -> E. x E. y ( x = u /\ y = v ) ) ).
|
30:29: | |- ( u = v -> ( E. x E. y ( x = u /\ y = u
) -> E. x E. y ( x = u /\ y = v ) ) )
|
31:18,30: | |- (. A. x x = y ->. ( u = v -> E. x E. y
( x = u /\ y = v ) ) ).
|
qed:31: | |- ( A. x x = y -> ( u = v -> E. x E. y (
x = u /\ y = v ) ) )
|