Nuprl Lemma : iff_preserves_decidability
9,38
postcript
pdf
A
,
B
:
. Dec(
A
)
(
A
B
)
Dec(
B
)
latex
ProofTree
Definitions
t
T
,
P
Q
,
Dec(
P
)
,
P
Q
,
,
x
:
A
.
B
(
x
)
,
A
,
P
Q
,
P
Q
,
False
,
P
Q
Lemmas
not
wf
,
iff
wf
origin
A,B:
. Dec(A) 
(A 
B) Dec(B)
A,B:. Dec(A) (A B) Dec(B)
T
Q Qx:A. B(x)
A
Q Q Q