CAS command question

[Arno K]

Bernard, vous etes correcte en disant que l'Anglais n'est pas votre langue maternelle.
I understand your point of view, learn the CAS better and you understand better, that is clear, I can learn to solve differential equations without decent knowledge of Analysis, but I won't understand the main parts.
Nevertheless I use the calculator as a tool which then has to do what I want, so the command right used with any expression is expected to provide the right side of that expression. So take a look at my idea of implementing the error-condition and two new commands.
Arno