Formulas
- PSL(2,7)
- Helly's selection theorem
- Polar set (potential theory)
- Porous set
- Positive harmonic function
- Primary pseudoperfect number
- Helmholtz decomposition
- Random compact set
- Ruffini's rule
- Simple function
- Stirling numbers of the first kind
- Hemicompact space
- Hemicontinuity
- Hopf algebra
- Hopf invariant