Rational
Rational numbers class, of the form x/y, provides main operations, including: +, -, *, /
MatrixS
Simple 2-dimensional matrix with basic operations, getting an element and resizing.
ArrayD
Growable array of doubles. Supports several operations, such as: get an element, resize, insert, remove.
ArrayT
Similar to ArrayD class, provides the same functions, works with every type by using templates.