Xcas Syntax / Prime Syntax (in particular computing in Z/pZ)

[jebem]

(03-08-2014 08:04 PM)Stefan Wrote:  I tried the following: 12 mod 13. However this also leads to an error. I get a result if I use a uppercase MOD, but does this mean that it uses then the HOME view MOD instead of the CAS view mod?

Same question here... We saw similar questions raised here before, concerning the consistency of uppercase/lowercase usage in Home, CAS, and the Catalog entries.

There are a few situations related to CAS environment that I am trying to understand (and failing so far):

1) When picking an uppercase function from the Catalog, it is copied to CAS entry area and converted to a lowercase function... that's what is happening here with this "MOD" command.
There is no "mod" expression in lowercase listed in the Catalog, as there are no trigonometric functions listed in lowercase - all of them are listed in uppercase (for instance, "SIN", "COS", "TAN", and all of them will be converted to lowercase when displayed in the CAS entry area).

2) Also, when we manually type a function in the CAS entry area, it will be in lowercase as well (that's the default).
So far, it looks to be consistent with point (1).

3) Now, after pressing the Enter key, usually the above functions are listed in the history area as uppercase... so it seems that CAS will "digest" these functions in uppercase, after all.
The question is: how many? All of them?

4) After that, when we copy one expression from the history area to the entry area, the functions are converted back to lowercase! Again, it looks to be consistent with points (1), (2) and (3).

5) However, due to a unknown cause (at least to me!), some functions, like the "mod" here, are not being converted to uppercase by the system when we press the Enter key... and because the CAS system expect an uppercase expression, the result is a syntax error!
In fact, the "MOD" function is NOT converted back to lowercase when copying a expression (where it exists) from the history area to the entry area!

6) As I see it, the system/parser tables are not updated with all the functions/expression names that must be converted between uppercase and lowercase when being copied between the different areas (Catalog, CAS entry area, and history area). At least, the "MOD" function is not included.
So, there are a unknown number of uppercase functions in the Catalog that are invalid in CAS environment, due to this abnormal behavior, and for those we need to manually type them in uppercase to be accepted!
The question here is: How many of these Catalog functions/expressions are invalid in the CAS environment?

Does it make any sense at all? I'm sure it does for the good people working hard on this issues to be fixed in due time.
Me? I'm lost here. I have to read the HP user guides in deeper detail to see if I can find some answers.