The QuantifierElimination package has been added in Maple 2023.
However, in the following example, the old (yet not obsolete) RegularChains:-SemiAlgebraicSetTools:-QuantifierElimination command can solve the problem, but strangely, the new QuantifierElimination:-QuantifierEliminate command simply returns an error. 
 

Download QEbug.mw

Code: 

QuantifierElimination[QuantifierEliminate](forall([x, y, t], Implies(And(x^3 + y^2 - x = t, And(t^2 = 4/27, t < 0)), x^2 + y^2 >= rho)));

So, is there any bug in Maple's QuantifierElimination package?

As you can see, if I want to simplify the following expression, I shall have to run the simplify command three times, and if I add some assumptions, the global simplify command will no longer work! 

:-simplify(2*(x^2+1)^(1/2)*(x+y+(x+y)/(x*y-1))^2/(((1/2)*(x+y+(x+y)/(x*y-1))*(2*x+(x+y)/(x*y-1)+y)/(x^2+1)^(1/2)-(1/2)*(2*x+(x+y)/(x*y-1)+y)*(y+(x+y)/(x*y-1))/(x^2+1)^(1/2)+(x+y+(x+y)/(x*y-1))/x)^2*x));

Download collect_and_recurse)_invalid_arguments_to_coeffs_.mws

But here either Physics[Simplify] or evala@Simplify works (with a slightly different result, though). Does anyone know why?

Here is an apparent instance: 

Download incorrectAgain.mw

Why???
Quite evidently, its supremum cannot be 0. (There are, of course, other approaches to compute it symbolically, yet I just wonder about the cause of this bug.)

For two nonempty lists (of the same length), 

F~(list1, ` $`, list2); # space-dollarsign

is (almost) equivalent to 

zip(F, list1, list2);

However, it appears that in practice, using `~` can be faster than its equivalent zip version.
Here is a typical test: 

Download `~`_and_zip.mw

But I cannot find any explanations in the documentation (as well as What is Maple's equivalent to Mathematica's MapThread?). Does anyone know why?

For a list containing at least one element, 

F~(list0); # element-wise

is (almost) equivalent to 

map(F, list0);

However, it seems that in practice, using `~` can be faster than its equivalent map version.
Here is a typical test: 

Download `~`_and_map.mw

But I cannot find any explanations in Comparison of element-wise operators and map function or Difference between 'map' and '~' (element-wise operation). Does anyone know why?