##  [Seifert–Van Kampen Theorem](/seifert-van-kampen-theorem) 

  ##  [Seifert–Van Kampen Theorem](https://puremath.quantumdictionary.io/seifert-van-kampen-theorem-0) 

  

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- Mathematics & Logic -

**Pure Mathematics Dictionary**

 







 

 

 

 



 

 

 

 

Definition

A fundamental theorem in algebraic topology that computes the fundamental group of a union of path-connected spaces from the fundamental groups of the pieces and their intersection via the pushout (amalgamated product) determined by the inclusion-induced homomorphisms.