Principal Ideal
An Ideal 
of a Ring 
is called principal if there is an element 
of such that
In other words, the Ideal is generated by the element
. For example, the Ideals 
ofthe Ring of Integers 
are all principal, and in factall Ideals of are principal.See also Ideal, Ring- Angle Bracket
- Angle of Parallelism
- Angle Trisection
- Angular Acceleration
- Angular Defect
- Angular Distance
- Angular Velocity
- Anharmonic Ratio
- Anisohedral Tiling
- Annihilator
- Annulus
- Annulus Conjecture
- Annulus Theorem
- Anomalous Cancellation
- Anomalous Number
- Anonymous
- Anosov Automorphism
- Anosov Diffeomorphism
- Anosov Flow
- Anosov Map
- ANOVA
- Anthropomorphic Polygon
- Anthyphairetic Ratio
- Antiautomorphism
- Anticevian Triangle