Envelope Theorem
Relates Evolutes to single paths in the Calculus of Variations. Proved in the general case byDarboux and Zermelo (1894) and Kneser (1898). It states: ``When a single parameter family of external paths from a fixed point
has an Envelope, the integral from the fixed point to any point 
on the Envelope equals the integral fromthe fixed point to any second point 
on the Envelope plus the integral along the envelope to the first point on theEnvelope, 
.''
References
Kimball, W. S. Calculus of Variations by Parallel Displacement. London: Butterworth, p. 292, 1952.
- Small Retrosnub Icosicosidodecahedron
- Small Rhombicosidodecahedron
- Small Rhombicuboctahedron
- Small Rhombidodecacron
- Small Rhombidodecahedron
- Small Rhombihexacron
- Small Rhombihexahedron
- Small Snub Icosicosidodecahedron
- Small Stellapentakis Dodecahedron
- Small Stellated Dodecahedron
- Small Stellated Triacontahedron
- Small Stellated Truncated Dodecahedron
- Small Triakis Octahedron
- Small Triambic Icosahedron
- Small World Problem
- Smarandache Ceil Function
- Smarandache Constants
- Smarandache Function
- Smarandache-Kurepa Function
- Smarandache Near-to-Primorial Function
- Smarandache Paradox
- Smarandache Sequences
- Smarandache-Wagstaff Function
- Smith Brothers
- Smith Conjecture