Before you ask, or waste time attempting, I see no way of solving this with my LogicProblem package.

@Markiyan Hirnyk He made a reply by private email that he otherwise would have made in MaplePrimes. He did this because of the disordering of Replies. It was a Reply that I was interested in reading. That is "starting to leave". I didn't say he that he had left. But, he hasn't participated since making that Reply three hours ago.

@Markiyan Hirnyk Two hours ago, in the Question thread "Maple 17 freezes", Alejandro Jakubi made the following Reply to a Reply by John Fredsted:

Changing location: I will answer to you by private mail as soon as possible. I prefer moving away, as this site is falling appart. In particular, the disorder on threads like this one is untolerable for me.

@Shanobadur Sure, it's just a minor modifcation.

Inverse:= proc(a,b,c,d)
local D;
    D:= a*d-b*c;
    if D=0 then
         error "Not invertible."
    else
        (d, -b, -c, a) /~ D
    end if
end proc:

Inverse(1,2,3,4);

@J4James Your solution treats a, b, and c as if they were scalars; and makes U = -6*a*i + b*j + c*k and likewise for V.

@YasH 

M:= Matrix(2, 2, [1,2,3,4], order= Fortran_order);

CodeGeneration:-Fortran(M);

      cg3(1,1) = 1
      cg3(1,2) = 2
      cg3(2,1) = 3
      cg3(2,2) = 4

The order in which the entries are filled in the Fortran program is not Fortran order. Fortran order would be cg3(1,1), cg3(2,1), cg3(1,2), cg3(2,2).

It looks fine to me. Can you show an example of it not working?

@pepegna90 I can't execute your worksheet because I do not have the original 136 x 117 Array. Please upload the complete executable worksheet and any necessary data files.

@Mac Dude Change the procedure `print/delta` to

`print/delta`:= proc(x) local delta; delta*convert(x,`local`) end proc:

and likewise for `print/Delta`. By converting the variables to locals, they won't be able to cancel. Nor will the deltas cancel in an expression such as delta(y)/delta(x).

Your xpr2 was in fact a hidden thingy that just printed as delta. You can reveal the hidden nature of any expression with lprint:

lprint(xpr2);
delta(x)/x

@pepegna90 There is a bug in MaplePrimes that prevents file uploads from working about half of the time. Unfortunately, this has happened to your file. Please try uploading it again, or use a file hosting service.

@pepegna90 In order to diagnose your problem further, I need the actual worksheet instead of just a screenshot. Try uploading it here. Or post it on one of those file hosting services.

@Mac Dude I think that you should ask this in a separate Question thread. What do you want to do with a+b*(c+d)? Do you want to extract the coefficient of (c+d)?

@pepegna90 For now, use ArrayTools:-AddAlongDimension and don't try to do it with with(ArrayTools).

@Mac Dude Since delta is not a variable, there can be no meaningful response to limit(delta(x), delta= 0). To differentiate with respect to delta(x), I believe that you can use Physics:-Fundiff, but I can't tell you much more than that.

@Axel Vogt Sorry, I don't understand your Answer. Have you used alias?