[Illustration: Fig. 4]
We have now a relation of two positions,—the relation of position “A”
to position “B.” The relation is one of Directions and of Distances.
Proceeding from “A” in a certain direction to a certain distance we
reach “B.” Proceeding from “B” in a certain direction and to a certain
distance we reach “A.” Every position means two things; a direction
and a distance taken from some point which may be described as the
premise-point.