302
ON THE CONDITIONS FOR THE EXISTENCE
[400
4. The values of the determinants are
1234 = 3 x
1235 = 3 x
1245 =
1345 = 3 x
2345 = 3 x
a?ce + 1
a 2 de — 1
a 2 ë z - 1
abe 2 — 1
ace 2 + 1
o?d 2 - 3
abce + 4
abde + 2
aede + 4
ad?e — 1
ab 2 e — 1
abd 2 + 1
ac 2 e + 9
ad 3 — 3
b 2 e 2 - 3
abed +14
ac 2 d — 3
acd 2 - 9
b 2 de + 1
bede + 14
ac 3 — 9
b 3 e - 3
b 2 ce — 9
6c 2 e — 3
bd 3 - 8
b 3 d - 8
b 2 c 2 + 6
b 2 cd + 2
b 2 d 2 + 8
bed 2 + 2
c 3 e — 9
c 2 d 2 + 6
5. The syzygetic relation with (/, J) is given by means of the identical equation
= -6I.HU+9J. U,
y*>
— 4 xy 3 ,
Qx 2 y 2 ,
-
¿c 4
a ,
36 ,
3c ,
d
b ,
3c ,
3 d ,
e
a,
36 ,
3c ,
d ,
b,
3c ,
3 d ,
e ,
or, as this may be written,
(1234, 1235, 1245, 1345, 2345$a, y) 4 = - 6/. HU + 9/. TJ,
where HU is the Hessian of U,
ac + 1
ad + 2
ae + 1
be + 2
ce + 1
b 2 -1
6c -2
bd + 2
cd — 2
d 2 - 1
c 2 - 3
6. That is, we have
1234 = ( ac- b 2
4 . 1235 = (2ad- 2bc
6 . 1245 = ( ae + 2bd
4 . 1345 = (2be - 2cd
2345 = ( ce — d 2
, o$—6/, 9J),
, 46][- 6/, 9/),
3c 2 , 6c $-6/, 9/),
, 4d$- 6/, 9 J),
, c$-6/, 9J).
7. The determinants thus vanish if (I, J) = 0, that is, for the root system 31 ;
they will also vanish without this being so, if only
SJ \ac — b 2 ad — be ae + 2bd — 3c 2 be — cd ce — d 2
26
6c
2 d
/SJ \
and we may omit the first member Uj =), since if the remaining terms are equal