Recovering a "MAS" autosaved backup file is very easy; I do it very often. Pull down the File menu => Recent Documents => Restore Backup. That's it.

@Markiyan Hirnyk It's difficult for me to give concrete examples because I don't remember exactly what the old titles were. However, an example of a class of title changes that I find unhelpful are those that contain the precise text of an error message. I would rather see that precise text than simply something such as "Error in dsolve."

Often titles are changed to include words with very low information content. A recent example of this is a title that was changed to "Problem with procedure." In that case, all three words have very low information content.

Would you please comment specifically on the editing of the titles of Questions? A very large number of Questions have their titles edited in a way that I find unhelpful. For one thing, I think that the specificity of the titles is often drastically reduced, which will make the topic harder to find by a search engine. However, I do think that the editing of titles for spelling is appropriate as it improves searchability.

@vv Since Maple 12, the set ordering is predictable, but not specifiable by the user. See option setorder at ?maple.

@John Fredsted Yes, I realized after posting that I had given a bad Answer. I thought that I deleted it, but I guess not. Well, might as well let it stand now.

Part of the confusion is that the indexing is probably pointless if sets are used.

@Markiyan Hirnyk

In all fairness, you must recuse yourself from any moderation in this thread.

@vv Did you try to make two consecutive calls to Normalize with different input and no intervening restart?

Normalize([1,3,1,3,2,2,4,4]);
Normalize([2,4,4,1,2,2,3,3]);

@Joe Riel Why does your first procedure not need forget but mine does?

@vv No, my two examples were meant to illustrate the same situation: a matrix with equal eigenvalues for which it is easily seen that any vector is an eigenvector.

Okay, I was wrong about the usualness of defective matrices.

@vv I wasn't trying to say that those matrices were defective! I was providing simple examples whereby the OP could easily verify that their "understanding" was wrong.

I think that the documentation at ?FAIL is adequate, and what could be more obvious to find?

"Semi-Boolean" means, as you guessed, that the function returns true, false, or FAIL, with FAIL meaning "I can't decide." A return of true means that the identity is true for all complex values of the variables under the current assumptions (if any), except those causing singularities.

This verification works:

verify(cos(u)+sin(u), sqrt(2)*cos(u-Pi/4), expand);

This one incorrectly returns false:

verify(cos(u)+sin(u), sqrt(2)*cos(u-Pi/4), simplify);

And even this incorrectly returns false:

is(cos(u)+sin(u) = sqrt(2)*cos(u-Pi/4));

Very disappointing. This last one I considered the most reliable of the three.

@John Fredsted The sums that we are looking at are of consecutive odd integers not necessarily starting at 1. For example, 5+7+9 = 21.

@Kitonum You wrote:

The original issue does not indicate that the numbers must be positive.

Yes, but it's a very reasonable assumption that that was what was intended, and both you and Joe made use of it. There's nothing interesting or new about the solutions containing negative summands.

You can lose also positive solutions.

You're right. It should be changed to

select(type, sols, set(name = nonnegint))

@Kitonum 

sols:= [isolve(sum(2*(m+i-1)+1,i=1..n) = 3375)]:
S:= select(type, sols, set(name = nonnegint));
S:= [seq(eval(Sum(2*m+1+2*k, k= 0..n-1), s), s= S)];

S := [Sum(31+2*k, k = 0 .. 44), Sum(99+2*k, k = 0 .. 26), Sum(111+2*k, k = 0 .. 24), Sum(211+2*k, k = 0 .. 14), Sum(367+2*k, k = 0 .. 8), Sum(671+2*k, k = 0 .. 4), Sum(1123+2*k, k = 0 .. 2), Sum(3375+2*k, k = 0 .. 0)]