Fundamental circuit

Fundamental circuit --- фундаментальный цикл.

It is easy to see that the addition of a chord to a spanning tree of a graph creates precisely one circuit which is called a fundamental circuit. In a graph the collection of these circuits with respect to a particular spanning tree is called a set of fundamental circuits. Any arbitrary circuit of the graph may be expressed as a linear combination of the fundamental circuits using the operation of ring-sum. In other words, the fundamental circuits form a basis for the circuit space.