[CAS] Detection of errors in the program editor

[compsystems]

(10-20-2016 08:05 PM)Tim Wessman Wrote:  

(10-20-2016 06:06 PM)compsystems Wrote:  the following statement the (CAS HPP-PL) compiler must detect the error
...
"Error: is not possible to determine the logical value of a = 5"

Why?

I can perfectly well determine if that is true or not. If a is not equal to 5, then it is false...

if 'a' is not defined I can not say anything
purge(a); 'a' not contain any object

a=5,It is indeterminate and no false