22 
MR. A. B. KEMPE OFT THE THEORY OF MATHEMATICAL FORM. 
125. For example in the case of the system of fig. 24, although all the graphical 
units are alike if taken apart from the barbed lines joining them, the two triads 
a, b, c and d, e, f are distinguished because plain lines are distinguished from wavy 
ones. If we ignore the difference between straightness L and waviness W, we are 
really dealing with the eight units a, b, c, d, e, f L, W, and instead of dealing 
with units a, b, c, &c., are really dealing with the triads «LW, 5LW, &c. When 
we regard the two triads a, b, c and d, e, f as distinguished, we deal with corre¬ 
spondences represented by the constituent consisting of the first, or last, nine rows 
of the table at the end of the section, in which it will be seen that L and W remain 
identically-correspondent, and the correspondences are such as would exist if L and 
W were distinguished. When we ignore the difference between straightness and 
, a b c d e f LW 
wavmess, we admit correspondences such as 7 , , TTr T . 
r d e j a b c W L 
The table representing the whole system of eight units is as follows :— 
abode f LW 
a b c e f d L W 
a b c f d e L W 
b c a d e / L W 
b c a e f d LW 
b c a f d e L W 
c a b d e f L W 
c a b e f d L W 
c a b f d e L W 
d e f ab c WL 
d e f b c a WL 
d e f c a b W L 
e f d ab c W L 
e f d b c a WL 
e f d c a b W L 
f d e a b c W L 
f d e be a W L 
f do cab W L 
