Nuprl Lemma : inv_funs_sym
12,41
postcript
pdf
A
,
B
:Type,
f
:(
A
B
),
g
:(
B
A
). InvFuns(
A
;
B
;
f
;
g
)
InvFuns(
B
;
A
;
g
;
f
)
latex
ProofTree
Definitions
,
t
T
,
P
&
Q
,
InvFuns(
A
;
B
;
f
;
g
)
,
P
Q
,
x
:
A
.
B
(
x
)
Lemmas
tidentity
wf
,
compose
wf
origin
A, B:Type, f:(A
B), g:(BA). InvFuns(A;B;f;g) 
InvFuns(B;A;g;f)
A, B:Type, f:(AB), g:(BA). InvFuns(A;B;f;g) InvFuns(B;A;g;f)
T Qx:A. B(x)