You don't show the call to setup_R but, from the code you've posted, I get the impression that you're expecting those various use statements to occur at that time. They don't! They occur at compile time. See:

• use - load in a module at compile time
• lib - manipulate @INC at compile time

Perhaps require would be a better choice. See:

• require - load in external functions from a library at runtime

"The reason I have not used strict at the beginning is that it makes my program to have more errors."

Sorry, but that's completely incorrect. strict only reports problems; it doesn't create them.