Nuprl Lemma : union-deq_wf
0,22
postcript
pdf
A
,
B
:Type,
a
:EqDecider(
A
),
b
:EqDecider(
B
). union-deq(
A
;
B
;
a
;
b
)
EqDecider(
A
+
B
)
latex
Definitions
union-deq(
A
;
B
;
a
;
b
)
,
EqDecider(
T
)
,
sumdeq(
a
;
b
)
,
sum-deq(
A
;
B
;
a
;
b
)
,
P
Q
,
Prop
,
b
,
x
:
A
.
B
(
x
)
,
t
T
Lemmas
assert
wf
,
iff
wf
,
sum-deq
wf
,
sumdeq
wf
,
deq
wf
origin
A, B:Type, a:EqDecider(A), b:EqDecider(B). union-deq(A;B;a;b) 
EqDecider(A+B) A, B:Type, a:EqDecider(A), b:EqDecider(B). union-deq(A;B;a;b) EqDecider(A+B) 
Q
bx:A. B(x) T