Gauss's Lemma
Let the multiples 
, 
, ..., 
of an Integer such that 
be taken. If there are an Evennumber 
of least Positive Residues mod 
of these numbers 
, then is aQuadratic Residue of . If is Odd, is a Quadratic Nonresidue. Gauss'slemma can therefore be stated as 
, where 
is the Legendre Symbol. It was proved byGauß 
as a step along the way to the Quadratic Reciprocity Theorem.
- Korselt's Criterion
- Kovalevskaya Exponent
- Kozyrev-Grinberg Theory
- k-Partite Graph
- Kramers Rate
- Krawtchouk Polynomial
- Kreisel Conjecture
- Kronecker Decomposition Theorem
- Kronecker Delta
- Kronecker Product
- Kronecker's Polynomial Theorem
- Kronecker Symbol
- Krull Dimension
- Kruskal's Algorithm
- Kruskal's Tree Theorem
- KS Entropy
- k-Statistic
- k-Subset
- k-Theory
- k-Tuple Conjecture
- Kuen Surface
- Kuhn-Tucker Theorem
- Kuiper Statistic
- Kulikowski's Theorem
- Kummer Group