Category. Special quantities
Category. B, P points
g, h, m, w straight lines
AWAY, g(Category; B) Straight through points A and B.
gCategory Half-straight line with the starting point A
[AC Half-line with the starting point A through the point G
[AWAY] Line with the endpoints A and B
k (M; r) Circle around M with radius r
k1 (M; r) Inside of k (M; r)
ka (M; r) Appearance of k (M; r)
B. The relationship
D. Illustrations