Can we use circuits we designed in the previous sections of a project as components in subsequent sections?
Can we use circuits we designed in different files and import them to use as components?
Unless specified otherwise, you may use circuits designed in a section of the project in subsequent sections. For example, in project 1, you may use your parity circuit in pf4.
In general, it is possible to import and use circuits from other Logisim files. However, this is not allowed in the projects. So, you are not allowed to use a circuit you designed in project 1 as a component in project 2.