CIIAPITUE V. SUU LES GUOLPES D OUDUE p\ 
puis 
/v' = },T'J -H V'^'J, 
uo' = o(/-ti — .v:), 
.3o'+ lix'= l{r6 — t'i) -+- îji(ra,— 5-) + v(7cp — ^J;) 
_ y ( — I ) _ ,s- ( .9 — 1 ) 
2 2 
) 
+ AO S — O -t-VO'iS(/- 
Voici les groupes correspondants 
0, =r c/' =z rf/' — 0/' — I , ab — ùac, ac^caO 
ad — da^ bc — cb%^ cd — dcO, bd — dbc 
i/aP^iO, b'' = cP =i dP = (i'> = I , ab — bac, ac — ca 
ad=da%^ bc — cbd, cd — dc, bd = dbc 
a'' = 0, bi> — c>' = di' — 0/' =: I , ab ~ bac, ac — ca 
ad — da, bc = cb^, cd—-dc, bd = dbc 
/rt/'=0, bi'= c''= dP=i}''=i, ab — bac, ac — c«0\ 
\^ ad — da, bc — cbt}, cd~dc, bd~dbU J 
a'' = 0, b'' = C = di' — 0/^ = I , ab — bac, ac ~ ca 0 " 
[ 
ad=da, bc — cbi)"-, ccl — dc, bd—db^, — i 
ai' — i), b'' C = di' = Oi> = 1 , ab = bac, ac = ca\ 
ad = da(), bc=cbO, cd — dc, bd — db y 
=z 0, bP — C — di> = 0'' = I , ab — bac, ac — ca 
' u 
ad — da^), bc=:cb(i", cd = dc, bd=db, 
{ai'=:?j, — ni> = bi' = C = I , ac-=ca, bc — cb?;, ab = ban), 
plus des groupes décomposables. 
85. Soit 
a!>—U, bi' = ci> = di' =z — ï , ab -—ba[)^, ac = ca, 
ad=zdaOP, ^ bc := cbW , bd = dbc, cd=dcO'\ 
