Nuprl Lemma : iff_symmetry
12,41
postcript
pdf
A
,
B
:
. (
A
B
)
(
B
A
)
latex
ProofTree
Definitions
t
T
,
P
Q
,
P
Q
,
P
&
Q
,
P
Q
,
,
x
:
A
.
B
(
x
)
Lemmas
iff
wf
origin
A, B:
. (A 
B) (B A)
A, B:. (A B) (B A)
T Q Q Qx:A. B(x)