There are different ways to organize the files in a complex design project. Normally one has a number
of different .act files that are combined using import directives to form the design. When an import directive is encountered, the ACT tools search for the specified file by first looking in the current directory, followed by the directories from $ACT_PATH, followed by $ACT_HOME.
This means that the best way to keep imports consistent throughout a specific project is to set ACT_PATH to the root of the project directory, and then import namespaces relative to that root path. The standard library is organized this way, so that all the namespaces can be accessed relative to the root of the install directory ($ACT_HOME/act).