Old Macsyma bugs still present



I dug up this discussion of some integration problems in Macsyma, and a
test of cvs maxima shows they are still there for us:

http://library.wolfram.com/mathgroup/archive/1990/Nov/msg00033.html


Key points:


"I only fixed MACSYMA a few months ago to get e.g. 
integrate(sqrt(x+1/x-2),x,0,1);  -> 4/3, instead of -4/3 ."


Significant, nontrivial integration problem:

(c1) /* The following gives the wrong answer: */
     integrate(sqrt(2-2*cos(x)),x,0,2*%pi);

(d1)                             0

(c2) /* Here's the reason why: */
     /* Just look at the indefinite integral and then 
        take limits: */
     integral: integrate(sqrt(2-2*cos(x)),x);

                                  4
(d2)                 - -----------------------
                                  2
                               sin (x)
                       sqrt(------------- + 1)
                                        2
                            (cos(x) + 1)

(c3) upper_limit: limit(integral,x,2*%pi,minus);

(d3)                            - 4

(c4) lower_limit: limit(integral,x,0,plus);

(d4)                            - 4

(c5) upper_limit - lower_limit;

(d5)                             0

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