Prepare to have your mind blown, friend, try `type trapz` or `type cumtrapz` in Matlab and read Mathworks-written m-file code to your heart's content (but if yo

Prepare to have your mind blown, friend, try `type trapz` or `type cumtrapz` in Matlab and read Mathworks-written m-file code to your heart's content (but if you do, you're disqualified from ever contributing to Octave). Or even try `edit xlsread` to edit that source code. Less excitingly, read its EULA. I can't find a copy of it because they don't publish it, but I do remember a part that allowed you to modify and distribute Mathworks-written m-code to other Matlab license holders.