Hi,
1. I've successfully built and installed rc4 on an i686-linux-gnu box
with clisp-2.29
2. The testsuite worked, with one minor exception in rtest15:
/* ********************** Problem 4. *************** */
%Input is
1
INTEGRATE(SQRT(- 2 + - + x), x, 0, 1)
x
The result is
4
- -
3
Using ratsimp
Using ratsimp
This differed from the expected result:
4
-
3
Actually -4/3 is also correct if you use the negative branch
of the SQRT function, although I don't know if this is
intended.
3. It seems that TAYLOR is somewhat more clever than the documentation
would indicate. Consider:
(C1) f(x):=1+1/x+exp(-x)*(1+1/x);
1 1
(D1) f(x) := 1 + - + EXP(- x) (1 + -)
x x
(C2) taylor(f(x),x,inf,2);
1 1 - x
(D2)/T/ 1 + - + . . . + (1 + - + . . .) %E + . . .
x x
This is neither a Taylor or Laurent series, but is very useful in
assymptotic analysis of expressions. I don't know how robust this
behavior is, for example:
(C1) taylor(sin(x)/(1+x),x,inf,3);
TAYLOR encountered an essential singularity in:
SIN(x)
-- an error. Quitting. To debug this try DEBUGMODE(TRUE);)
Rather than giving an error, it might be nice to have the option of
keeping the sin (or any other essentially singular function, like
exp(-x)) explicit and taylor expanding the rest; i.e.,
sin(x)/x -sin(x)/x**2 + ...
In any event this behavior is undocumented.
David