Valuation Ring
Let 
be a non-Archimedean valuated field. Its valuation ring 
is defined to be
The valuation ring has maximal Ideal
and the field
is called the residue field, class field, or field of digits. For example, if 
(
-adic numbers), then 
(-adic integers), 
(-adic integers congruent to 0 mod ), and = GF(), the Finite Field of order . - Pyramid
- Pyramidal Frustum
- Pyramidal Number
- Pyritohedron
- Pythagoras's Constant
- Pythagoras's Theorem
- Pythagoras Tree
- Pythagorean Fraction
- Pythagorean Quadruple
- Pythagorean Square Puzzle
- Pythagorean Theorem
- Pythagorean Triad
- Pythagorean Triangle
- Pythagorean Triple
- Pépin's Test
- Pépin's Theorem
- Pólya-Burnside Lemma
- Pólya Conjecture
- Pólya Distribution
- Pólya Enumeration Theorem
- Pólya Polynomial
- Pólya's Random Walk Constants
- Pólya-Vinogradov Inequality
- Pósa's Theorem
- Q