Only two files in the file Macro

Hi, everyone.
I am a new ROOT user. My confusion is that when I read the Reference Guide 2.3 - ROOT as function plotter, I found that I do not have the file slits.C on my disk. And only Dialogs.C fileopen.C in the file Macro. Is there anything wrong with my ROOT?

In $ROOTSYS/documentation/primer/macros/

Thank you for your time! Could you solve the problem about RooFit in my new topic? Please help!