Im currently reading the laymans theory behind the job shop problem written in OR TOOLS. I have come by an annotation that I do not understand, hopefully somehow here could help me.
In the above link, step 6.1.3 the notation l is introduced as a part of the conjunctive arcs, can anyone see what this l is a notation for? It isn't in the theory "they" introduce and I can't seem to link it to general job scheduling or mixed graph theory.
Kind regards