##  [Incidence Algebra](/incidence-algebra) 

  ##  [Incidence Algebra](https://algebra.quantumdictionary.io/incidence-algebra-0) 

  

 [![Algebra](/sites/default/files/styles/large/public/2026-01/Algebra.png.webp?itok=3pHxBnUF)](/topic-specific-dictionaries/pure-mathematics/algebra)

- Pure Mathematics -

**Algebra Dictionary**

 







 

 

 

 



 

 

 

 

Definition

The algebra of functions defined on intervals [x,y] of a locally finite partially ordered set (poset), with addition pointwise and multiplication given by convolution (f * g)(x,y) = sum_{x ≤ z ≤ y} f(x,z) g(z,y); the zeta function and Möbius function live in this algebra.