@Carl Love 

Works fine. Thank you Carl. How would a Joe Maple user ever find those things without you pundits? (:>

@Kitonum 

Thank you for your answer but  it doesn't work. Would be sufficient to know how to tell typeset to stop using the italic 'L' instead of 'laplace' sice this confuses the code interpreter or what its is.

@Carl Love  Thanks for coming back. Tried F1 and help from the menue. Same thing.

@ecterrab 

Hi Edgardo, you promised somewhere that it would be possible (within a week in that doc) to define a spinor from the Setup. Is that implemented already.  Couldn't find anything in the Help text.

@ecterrab 

Thanks Edgardo,  at least something to go through.

@vv 

That's quite sad, that a theorem can give us that much trouble because it declares something impossible. There is probabbly no reason to doubt Richardson but one can hope, gravitation and airlift, that somehow a smart ass guy comes along and shows us how Richardson is still valid but he lifts him up with some complementary trick, it happens all the time, think of the STED Microscope. Those of the future like to believe those things, the others belive in Richardson who will continue to be a great man all along. We are where we are because we kicked the impossible in the ass and made it happen, all within the allowed. Long speech but the thing ist interesting.

@Markiyan Hirnyk 

... anyway, maple does a lot of other great things, let's be happy for now but some genius should write a perfect simplify code and get the Nobel Price for it, cause simplifying is really a devillish thing.

@vv 

and I had that clear but ... that's not what you expect from a up to 2,000 Bucks CAS after 250 years of development.

Or I am just ungrateful ... but what's all the bling bling for if the simple stuff bugs you to death? It's still agreat program but it could be even greater by a tiny bit ;-).

@vv 

my problem is much simpler. Start from

-n*mu+ln(product(mu^x[i]/factorial(x[i]), i = 1 .. n))

which is the log likelihood for a Poisson random variable with parameter mu.

Now you have to diff it with respect to "mu" to find the mu for which the loglike is extremum/max. If you

do that with the above expression, limbo waits for you, for understandable reasons if you consider the product rule and the n products to diff. But using the equivalent

-n*mu+(sum(x[i], i = 1 .. n))*ln(mu)-ln(product(factorial(x[i]), i = 1 .. n)),

which Maple can't find, it's a breeze and you get your mu_max which is x_bar.

All this shows, as so often, apparently very simple expressions can have the devil in them and even products as sophisticatedly advanced as Maple 2016 can't handle them, cause someone should have foreseen this case and programmed it, but you cannot foresee everything, so we still need as you say paper pencil and the rare brain ;-). Thanks for your help.

@vv 

The expresion is actually part of a simple derivation (education) of a ML estimator for mu with Poisson errors. You have to take the derivative of that expression and set it = zero to find the extreme value of the log likelihood. If you do that with the short version you end up in limbo whereas the long John works easy and simple exactly as shown in the book ;-) .

In order for this thing to work Maple needs to have an operation that converts an explicit sum like

x[1]+x[2]+x[3]+ ... [n]  to sum(x[i], count(i)) or something of that style. It may exist but who knows such things, as Ramakanda so aptly asks.

@vv 

...it works for any number except n ;-)

@ecterrab 

In equ. (2) it is Nabla and not Nabla^2.

Sorry

@ecterrab 

but I suppose you're interested in anything concerning the proper function of the physics package. Here is what I  found, if it is not some error of my side.

Operator algebra. You want to quantize p.e. the p^2 in some q-operator equ.:

p^2;  (1)

subs(p= - i h Nabla^2, (1));   (2)

Then multiply with some function g(X)

(2) . g(X);  (3)

The Libray:-ApplyP... ((3));  then doesn't get it right. It can't handle the i and h properly, the result seems to be undefined.

Same little thing in index notation works fine.

I am using you last July 28 file with maple 2015.

Regards

Dieter

@ecterrab 

... but I had to use the dreaded IE in order to see the updates, Firefox didn't get it even after all the cleaning and flushing recommended by the experts. Thanks a lot.

Dieter

@ecterrab 

Where could i find that, Edgardo? What I get on the page is the Physics.zip (1.04 MB), which contains the Physics.mla from 2013 while the 2015 stuff is up tp date.  Am I somehow lost?