Maxima Digest, Vol 7, Issue 7



>On the other hand, the noun/verb system for functions from expressions
>to expressions has some utility.  It lets you express the notion of an
>unevaluated version of a function; thus 'diff(y,x) remains 'diff(y,x)
>(even after re-evaluation), and does not become 0.  This allows you to
>later substitute some expression in x for y, and then force the
>explicit calculation of the differential using ev(...,diff).  
>
It seems to me noun forms should not be necessary.  If one declares y to 
depend on x this
signals maxima to leave diff(y,x) in symbolic form (as it cannot be 
simplified further). If you substitute
y=sin(x) then the simplifier should fire and replace diff(sin(x),x) by 
cos(x)
So where is the need for a noun form?

After some experimenting I see that neither limit nor integrate do seem 
to take a "depends" declaration
into account. And neither does freeof....  But if you write y(x) instead 
of depends(y,x) then the behaviour
is correct....

Michel