Has anybody seen the unit palette beeing empty? 

This is new to me. I normally use the unit entry in the favourites but this time wanted to try Maple presets.

I am looking for a command that extracts sqrt(2) from

sqrt(4 + (-2*x - 2)*y)

The expression above is a subexpression of a larger expression generated by Maple (an integral).
In this situation manual workarounds are impractical and errorprone.

Ideally Maple should return

sqrt(2)*sqrt(2 - (x + 1)*y)

I tried simplify, factor, collect and so on...

In case that there is nothing (which I doubt):
Why is Maple not having simple commands that do extraction (and absortion/inclusion) of factors?

(extract and absorb are names not used so far that would be easy to remember.)  

Update - example of an expression:

expr := Int(sqrt(-2*alpha^2*x - 2*alpha^2 + 4)/(sqrt(-alpha^2 + 1)*(-alpha^2*x - alpha^2 + 2)), alpha = 0 .. z) = EllipticF(z, sqrt(2*x + 2)/2)

When clicking on a pink error message I get this

Can someone explain what is going on? Quite unusual for me all this.

I do not have a server to white list. What can I do about it?

Is that Sucuri thing safe?

By symbolic regression I mean an algorithm that determines a model (fit function) that fits best to a data set.

Are there any commands, packages, libraries or MaplesPrime post that are helpful in this regrad?

Edit: For the data set below a symbolic regression could ideally algortihm return "simple" models (formulas)  that use a "minimal" number of terms.

Download regression_dataset.mw

I do not understand the following typesetting example from this helpage.

Download Typeset.mw

Why the Typeset call when the output does not change. Is the helppage maybe broken? It says Examples but lists only one.

If MapleSoft read this: Some more typesetting examples would be helpfull.