THE GENERAL LINEAR GROUP. 303 
FIG. 36. 
360. Type IV. In the first place let /’ be the line at in- 
finity, and let A be in finite space, Fig. 36. The triangle 
AP@Q is transformed into AP,@,. Along AA”, k= aS : 
along AA’, k = ae Hence we have 
AAPQ) AP;.A Qi siné 
AAPQ  AP.AQsino 
R= 
Poh \ 
Fic. 37. 
