Definition:Undecimal Notation

Definition
Undecimal notation is the technique of expressing numbers in base $11$.

Every number $x \in \R$ is expressed in the form:
 * $\ds x = \sum_{j \mathop \in \Z} r_j 11^j$

where:
 * $\forall j \in \Z: r_j \in \set {0, 1, \ldots, 9, 10}$

In order to be able to represent numbers in such a format conveniently and readably, it is necessary to render the digit $10$ using a single character.