using diff() in a program

[leprechaun]

There are some citations I found very important.

1)
Cas function calls from home, using fully qualified names or not, have all the parameters defined as ‘do not evaluate’.
->This seems to be the main subject to change in the latest update. You need to EVAL() the local variable for the call. Otherwise it is just the name that is used. That is where EVAL() and QUOTE() come in.

2)
This is solved by allowing you to use strings as parameters for the CAS. These strings will be parsed at the time of the CAS function call.
->As usual I would say

3 -(local variables)
These are temporary and local to this specific call of the function.
->Something that personally I was not aware of. My intuition dictated that a local variable would be passed by value, but it seems that a local variable is indeed invisible outside the function.

Please correct me if I am talking nonsense. i don't want to baffle people but sometimes the view of a different person can be enlightening.