- array
- array algorithm
- array by diagonals
- array by squares
- array grammar
- arris
- arrival instant
- arrival pattern
- arrival process
- arrival time
- arrow
- arrow diagram
- arrow function
- arrowhead
- arrowhead curve
- Arrow-Hurwicz-Uzawa gradient method
- Arrow-impossibility theorem
- Arrow, K.J.
- Arrow paradox
- AR-sequence (= Auslander-Reiten sequence)
- art-gallery theorem
- articulation
- articulation point
- articulation set
- articulation vertex