I have a question about the different possibilities for calling a little used function from a package. It seems that there are three ways to do that:

1) Load the package and use te short form of the call e.g.
> with(combinat);
>randperm(5);

2) just load the command e.g.

>with(combinat,randperm);
>randperm(5);

3) use the long form of the call e.g.

>combinat[randperm](5)

4) with the use command e.g.

I like to use Maple as an informal  text editor for math correspondence. (I do not use Tex and am firmly committed to not learning Tex. Principled laziness.) I usually insert a Document block in a new worksheet, type my letter utilizing all the wonderful automatic formatting-powers, symbols, integrals, etc. easily available in Maple and then print the resulting document as a pdf and email it. It is much more readable for me and for the person receiving the document.

I was trying to solve a VERY simple system of 2 equations,{ eq1,eq2}, for the variable d which appears only once to the first degree with coefficient 1. That is grade school algebra. Maple 15 refused; it needed help.

restart;
eq1:=s=a+b+c+d;
                    eq1 := s = a + b + c + d
eq2:=s=2*(a+b)*(a+c)*(b+c);
             ...

It is never a good error message but I have not been able to find out whatit means.

Thanks,

I have a matrix m with 9 rows and 4 columns and when I enter the command below I get an error message:

num := product((z-(m[s,1]+I*m[s,2])),s = 1..9);
Error, Matrix index out of range

However, there is no problem if I use brute force: