Nuprl Lemma : iflift_1
4,23
postcript
pdf
A
,
B
:Type,
c
:
,
f
:(
A
B
),
x
,
y
:
A
.
f
(if
c
x
else
y
fi) = if
c
f
(
x
) else
f
(
y
) fi
latex
Definitions
Unit
,
P
Q
,
P
&
Q
,
P
Q
,
Prop
,
,
b
,
A
,
b
,
x
:
A
.
B
(
x
)
,
t
T
,
x
(
s
)
Lemmas
assert
wf
,
not
wf
,
bnot
wf
,
bool
wf
,
assert
of
bnot
,
eqff
to
assert
,
iff
transitivity
,
eqtt
to
assert
origin
A, B:Type, c:
, f:(A
B), x, y:A. f(if c
x else y fi) = if c f(x) else f(y) fi A, B:Type, c:, f:(AB), x, y:A. f(if c x else y fi) = if c f(x) else f(y) fi 
Q
Q
bA
bx:A. B(x)
T