Set Difference
The set difference 
is defined by
The same symbol is also used for Quotient Groups.
- Quindecillion
- Quintet
- Quintic Equation
- Quintic Surface
- Quintillion
- Quintuple
- Quintuple Product Identity
- Quintuplet
- Quota Rule
- Quota System
- Quotient
- Quotient-Difference Algorithm
- Quotient-Difference Table
- Quotient Group
- Quotient Ring
- Quotient Rule
- Quotient Space
- q-Vandermonde Sum
- R
- R-
- R+
- Raabe's Test
- Rabbit Constant
- Rabbit-Duck Illusion
- Rabbit Sequence