16-Cell
A finite regular 4-D Polytope with Schläfli Symbol 
andVertices which are the Permutations of (
, 0, 0, 0).
- Regular Local Ring
- Regular Number
- Regular Parameterization
- Regular Patch
- Regular Point
- Regular Polygon
- Regular Polyhedron
- Regular Prime
- Regular Ring
- Regular Sequence
- Regular Singularity
- Regular Singular Point
- Regular Surface
- Regular Triangle Center
- Regulus
- Reidemeister Moves
- Reidemeister's Theorem
- Reinhardt Domain
- Relation
- Relative Error
- Relative Extremum
- Relatively Prime
- Relative Maximum
- Relative Minimum
- Relaxation Methods