Nuprl Lemma : permute_list_length
4,23
postcript
pdf
T
:Type,
L
:
T
List,
f
:(
||
L
||
||
L
||). ||(
L
o
f
)|| = ||
L
||
latex
Definitions
x
:
A
.
B
(
x
)
,
i
j
,
||
as
||
,
{
i
..
j
}
,
t
T
,
P
Q
,
l
[
i
]
,
False
,
A
,
A
B
,
,
(
L
o
f
)
Lemmas
int
seg
wf
,
mklist
length
,
length
wf1
,
select
wf
,
non
neg
length
origin
T:Type, L:T List, f:(
||L||
||L||). ||(L o f)|| = ||L|| 
T:Type, L:T List, f:(||L||||L||). ||(L o f)|| = ||L|| x:A. B(x)
j
} T
Q
A
B