[Axiom-developer] about Expression Integer

[Francois Maltey]

Hello, 

Thanks for previous help, 
now I can compile a package and add spy-print inside !

I play whith expressions and I have theses questions :

1/ Can I (or cannot) remain Expressions as 

x+1/(y+1)             
y+1/(x+1)             

and do not have a single denominator.

2/ Can I go back from (xy+x+1)/(y+1) to x+1/(y+1) ?
Other cas have normal or partfrac fuction, or remain fraction as.

3/ When I expand a trig formula I cut x+1/(y+1) in x and 1/(y+1) 
not in xy/(y+1) and x/(y+1) and 1/(y+1). 

But perhaps my ideas aren't right ?

4/ I'm not sure that the results (xy+x+1)/(y+1) and ((x+1)y+1)/(x+1) 
are fine :

First the order of the variable is important, 
and the user (almost) can't force it, if he uses "n" and "x" variables.

Second the result is longer if the denominator is big.

5/ Of corse there is no problem in expand (cos (4*x+5y)),
but small problems appear with     expand (cos (4*x+5*y/2)) 
and a lot with                     expand (cos (4*x+5*y/(2+t+t^2+t^3))).

What is the better expand in the 3 cases.
Perhaps cos^4 x ... cos^5 y ... 
        cos^4 x ... cos^5 (y/2) ... 
        cos^4 x ... cos^5 (y/(2+t+t^2+t^3)) ... but I'm not sure.


I will be very happy if you can give me your advice, and tell me if
one or an other way of computation is impossible/not natural/too complex 
with axiom. 

Have a good day.

Francois