Formulas
- Lie algebra
- Range of a function
- Rank (differential topology)
- Rank of a group
- Rank of a partition
- Rank of an abelian group
- Rare Earth hypothesis
- Rate function
- Rational function
- Ratner's theorems
- Rayleigh quotient
- Lieb–Thirring inequality
- Real closed ring
- Real rank (C*-algebras)
- Rearrangement inequality