Nuprl Lemma : strong-subtype-member
0,22
postcript
pdf
A
,
B
:Type,
b
:
B
,
a
:
A
. strong-subtype(
A
;
B
)
{
b
=
a
B
b
A
}
latex
Definitions
x
:
A
.
B
(
x
)
,
{
T
}
,
P
Q
,
Prop
,
strong-subtype(
A
;
B
)
,
A
&
B
,
x
:
A
.
B
(
x
)
,
t
T
Lemmas
strong-subtype
wf
origin
A, B:Type, b:B, a:A. strong-subtype(A;B) 
{b = a 
B b A} A, B:Type, b:B, a:A. strong-subtype(A;B) {b = a B b A} 
x:A. B(x) Qx:A. B(x) T