Nuprl Lemma : strong-subtype-union
0,22
postcript
pdf
A
,
B
,
C
,
D
:Type. strong-subtype(
A
;
C
)
strong-subtype(
B
;
D
)
strong-subtype(
A
+
B
;
C
+
D
)
latex
Definitions
x
:
A
.
B
(
x
)
,
S
T
,
strong-subtype(
A
;
B
)
,
A
&
B
,
P
Q
,
Prop
,
x
:
A
.
B
(
x
)
,
t
T
Lemmas
strong-subtype
wf
origin
A, B, C, D:Type. strong-subtype(A;C) 
strong-subtype(B;D) strong-subtype(A+B;C+D) A, B, C, D:Type. strong-subtype(A;C) strong-subtype(B;D) strong-subtype(A+B;C+D) 
x:A. B(x)
T Qx:A. B(x)
T