Seifert–Van Kampen theorem
= Seifert–Van Kampen theorem
{wiki=Seifert–Van_Kampen_theorem}
The Seifert–Van Kampen theorem is a fundamental result in algebraic topology that provides a method for computing the fundamental group of a topological space that can be decomposed into simpler pieces. Specifically, it relates the fundamental group of a space to the fundamental groups of its subspaces when certain conditions are satisfied.