Fallbacks

Fallbacks are the recipes that are available to the planner or user if things go haywire. They are a safe set of moves that let a carrier leave the line. The fallbacks are not simple, and involve information about the process in question. For example, it would be unsafe to bring a carrier directly out of the line directly after acid.

The fallback recipe should start with the treatment in question, and end with a terminal station. The option to choose which exit should be checked, as this is a "bad case" usage of code. There should also be no upper bounds in the constraint section as that may cause an issue.

A possible explanation of the crash at ACMT was that one of the fallbacks had directly repeated treatments, a semi known bug.