Re: About rewrited expressions for power, log, exp and so.

Francois Maltey <[email protected]> writes:

[...]

| And mupad had 2 features which aren't (yet) in axiom expressions :
| 
| 1/ The assume command : 
| assume (a>1) ; limit (a^x, x=%plusInfinity)            --> %plusInfinity 
| assume (a=1) ; limit (a^x, x=%plusInfinity)            --> 1
| assume (a<1 and -1<a) ; limit (a^x, x=%plusInfinity)   --> 0
| assume (a<-1) ; limit (a^x, x=%plusInfinity)           --> "failed"

maple has same.  This is what Tim refers to in general as "provisos".

| 2/ the piecewise command :
| solve (a*(a-1)*x=a, x) 
| x = 1/(a-1)   if a in C \setminus {0, 1}
| x in C        if a=0
| x in emptyset if a=1

this can be worked into Axiom, assuming we have provisos.

-- Gaby