Starting with version 1.5 of ProB, it is possible to customize where the parser will ProB will search for referenced files.
By default ProB will try to find files referenced from a machine (using SEES, INCLUDES, DEFINITON-files, etc) resolving paths as relative to the current machine or within the ProB standard library.
Commonly used files can be placed in a shared location, e.g. in the standard library (the stdlib directory in the ProB distribution) or any custom location.
The search path can be customized by defining a PROBPATH environment variable that contains a “:” separated list of directories to be searched, e.g.:
PROBPATH=~/myproject/common:~/myotherproject/common probcli model.mch
will resolved referenced files relative to model.mch, then in ~/myproject/common then in ~/myotherproject/common and finally in the standard library of ProB, stopping as soon as a file with the name being looked up is found.