> 1. selects a sub-collection B of A whose elements match the path pattern β, > 2. computes a new collection C as a function f of B and its neighbors, > 3. an

> 1. selects a sub-collection B of A whose elements match the path pattern β, > 2. computes a new collection C as a function f of B and its neighbors, > 3. and specifies the insertion of C in place of B into A. This sounds a lot like the presentation of comonads as directed containers (e.g. https://arxiv.org/abs/1408.5809 https://arxiv.org/abs/1408.5809).