Nuprl Lemma : l_member_non_nil
11,40
postcript
pdf
T
:Type,
x
:
T
,
L
:(
T
List). (
x
L
)
(
(
L
= []))
latex
Definitions
A
B
,
prop{i:l}
,
t
T
,
False
,
A
c
B
,
x
:
A
.
B
(
x
)
,
A
,
(
x
l
)
,
P
Q
,
x
:
A
.
B
(
x
)
,
,
Y
,
||
as
||
Lemmas
select
wf
,
length
wf1
,
nat
wf
origin
T:Type, x:T, L:(T List). (x 
L) 
(
(L = [])) T:Type, x:T, L:(T List). (x L) ((L = [])) 
B T
B
x:A. B(x)A l) Qx:A. B(x)