基き本ほん群ぐん

noun

fundamental group

A concept in algebraic topology; the group of homotopy classes of loops based at a point in a topological space.

• 円えん周しゅうの基き本ほん群ぐんは整せい数すう群ぐんと同どう型けいである。

  The fundamental group of the circle is isomorphic to the group of integers.