Corollary 7.13.
Assuming that:
(
U
,
V
)
is
C
-relevant
to
(
X
,
Y
)
U
1
,
U
2
,
V
1
,
V
2
are independent copies of
U
,
V
Then
(
U
1
+
U
2
,
V
1
+
V
2
)
is
2
C
-relevant
to
(
X
,
Y
)
.