Probability(X<0) = 0.5
Probability(Y<0) = 0.5

Probability (X*Y<0) = 0.1193124670

@vv  The answer you produced is for 4 normal distributions.  And Maple computes that correctly.

If all distributions in Maple were classified as Normal, Maple would arrive at the same answer Mathematica came up with.

Alternatively it could suggest that it was user error and Mathematica was actually calculating the CDF of four Normal distributions and not two normal and two uniform distributions.  And in a haste to broadcast the error, the op didn't realize the difference. 

Markiyan, are you sure Mathematica wasn't calculated with four normal distributions?

Maple 2016 offers the same as Maple 12 but you have to tell it

Which one is right?  equating the two (mathematica and maple) brings up a fail

Maple 12 outputs

@acer thanks for filling in the missing versions.  I didn't realize I had missed so many.  I was using mapleprimes to search for update release notices as a rough guide.

As for calculating the computed dates, I based it on the month they were released in. 

version number = year + 1/12 * (month released in -1 ) # for some rough positioning in the graph.

@Carl Love ... but you would loose the web browser bookmarking list going from computer to computer.  It would be better as a bookmark at mapleprimes.

The only way to reserve a question or post is to favorite it.  Can we add topics of lesser interest but still interesting as a bookmark?  Would be nice to add bookmarks.

@Markiyan Hirnyk Any translator will be buggy and get more so with each new passing version if they are not supported.

I only played with it once.

@Markiyan Hirnyk Yes there is http://library.wolfram.com/infocenter/Demos/188/ 

You wrote "They likely need not it."   Why not?

Similarily Mathematica has an outdated Mapleconverter package.  It has been pointed out before that MmaTranslator package is outdated.  That should be understandable, it is great for users of Maple/Mathematica but not so great for Maplesoft (ie resource allocation). 

I think you'll find these types of packages are not so greatly supported or updated by either Mathematica or Maplesoft.

What does Mathematica say?

I animated it ..

animate(implicitplot, [x*sin(t)+y*sin(2*t), x = -10 .. 10, y = -10 .. 10, thickness = 2], t = 1 .. 2*Pi)

.. but perhaps that provides nonsense.

What's the graph supposed to look like?

@Carl Love in your case has(ifactor(2^7,7))  will indeed be true, it's not really a flaw, it works by design.

Thanks for pointing out the inefficiency, I didn't realize that.

@Thomas Richard The .015 was for plotting purposes only, it was actually 18.01a

I'm pretty sure I haven't missed any releases (major or minor) after Maple 5

Which dot releases are missing?  With the exception of Maple 9.5, a major dot release and Maple 10 (which had 6 dot releases) the majority of the time one could expect 1 dot fix update per release.  Ok I see now why I shouldn't focus on dot releases - that being a dot release is a fix rather than a major platform release.