Harmonic Homology
A Perspective Collineation with center 
and axis 
not incident is called a Homology. A Homology is said to be harmonic if the points 
and 
on a line through are harmonic conjugates with respect to and 
. Every Perspective Collineation of period two is a harmonichomology.
References
Coxeter, H. S. M. Introduction to Geometry, 2nd ed. New York: Wiley, p. 248, 1969.
- Conical Spiral
- Conical Wedge
- Conic Constant
- Conic Double Point
- Conic Equidistant Projection
- Conic Projection
- Conic Section
- Conic Section Tangent
- Conjecture
- Conjugacy Class
- Conjugate Element
- Conjugate Gradient Method
- Conjugate Points
- Conjugate Subgroup
- Conjugation
- Conjunction
- Connected Graph
- Connected Set
- Connected Space
- Connected Sum
- Connected Sum Decomposition
- Connection
- Connection Coefficient
- Connectivity
- Connes Function