Hyperbolic Fixed Point (Differential Equations)
A Fixed Point for which the Stability Matrix has Eigenvalues 
,also called a Saddle Point.
References
Tabor, M. ``Classification of Fixed Points.'' §1.4.b in Chaos and Integrability in Nonlinear Dynamics: An Introduction. New York: Wiley, pp. 22-25, 1989.
- Residue (Congruence)
- Residue Index
- Residue Theorem (Complex Analysis)
- Residue Theorem (Group)
- Resolution
- Resolution Class
- Resolution Modulus
- Resolvable
- Resolving Tree
- Resonance Overlap
- Resonance Overlap Method
- R-Estimate
- Restricted Divisor Function
- Restricted Growth Function
- Restricted Growth String
- Resultant
- Retardance
- Reuleaux Polygon
- Reuleaux Triangle
- Reversal
- Reverse Greedy Algorithm
- Reverse-Then-Add Sequence
- Reversion of Series
- Reznik's Identity
- Rhodonea