310 Professor Haminton on Conjugate Functions, 
if the moment B were later than the moment a, or 
B¢A 
if B were earlier than 4. 
Now, without yet altering at all the foregoing conception of B—a, as the symbol 
of an ordinal relation discovered by the comparison of two moments, we may in some 
degree abridge and so far simplify all these foregoing expressions, by using a simpler 
symbol of relation, such as a single letter 4 or b» &c. or in some cases the character 
0, or other simple signs, instead of a complex symbol such as p—a, or p—c, &c. 
Thus, if we agree to use the symbol 0 to denote the relation of identity between two 
moments, writing 
A Os (31.) 
we may express the equivalence of any two dates B and a, by writing 
B—A=0, (32.) 
and may express the non-equivalence of two dates by writing 
B-A+O0; (33.) 
distinguishing the two cases when the moment B is later and when it is earlier than a, 
by writing, in the first case, 
B—A>O, (34..) 
and in the second case, 
B—aA<0, (35.) 
to express, that as compared with the relation of identity 0, the relation B—A is im 
the one case a relation of comparative lateness, and in the other case a relation of 
comparative earliness : or, more concisely, by writing, in these four last cases re- — 
spectively, which were the cases before marked (1.) (2.) (3.) and (4.) 
a= 0; (36.) 
a0, (37-) 
a>O, (38.) 
a<O, (89.) 
if we put, for abridgement, 
B—A=a, (40.) 
Again, if we put, in like manner, for abridgement, 
D—c=b, (41.) 
