Compute pushout complement (DPO step 1)

Given l: I → L and m: L → G, find K and morphisms ik: I → K, kg: K → G such that the square (l, m, ik, kg) is a pushout.

Usage

pushout_complement(l, m)

Arguments

l

ACSetTransformation I → L

m

ACSetTransformation L → G (match morphism)

Value

List with K (ACSet), ik (I → K), kg (K → G), or signals an error if gluing conditions fail.

Details

Requires the gluing conditions:

1. No dangling edges: deletion of a vertex doesn't orphan edges

2. Identification: distinct deleted items aren't identified by match