For a 2D parametric plot with only one parameter, in Maple we use plot([x,y,range]) but what about the case x and y are expressed by more than one parameter? How should I assign the range? For example I tried the following one

h := k[1]*k[3]+k[1]*k[4]+k[2]*k[4]:
x := k[2]/h:
y := (k[3]+k[4])/h:
A := seq(k[i] = 1 .. 2, i = 1 .. 4):
plot([x, y, A]);

But then I encountered the following error:
Error, (in plot) incorrect first argument [k[2]/(k[1]*k[3]+k[1]*k[4]+k[2]*k[4]), (k[3]+k[4])/(k[1]*k[3]+k[1]*k[4]+k[2]*k[4]), k[1] = 0.1e-2 .. 1000, k[2] = 0.1e-2 .. 1000, k[3] = 0.1e-2 .. 1000, k[4] = 0.1e-2 .. 1000]

For one parameter the above method doesn't make an error like the following:

x := t+1:
y := t^2:
A := t = 1 .. 2:
plot([x, y, A]);

So for more than one parameter, there should be another way to ask the plot. Does anyone know how to do that?

Assume you have a matrix A and somewhere you want to make a copy of it like B and working with them independently. Let's say you have a loop and after doing a proc on B again you have to make it equal to A. So changes on B shouldn't effect on A. What is the common way of taking such copies of A in Maple?

The following methods don't work.
 

A:=Matrix(3);
B:=A;
B(1,1):=1;
A;

A:=Matrix(3);
B:=subs(B=A,B);
B(1,1):=1;
A;

What I came up with is the following but it will look weird if one really needs to write something meaningless like *2/2.

A:=Matrix(3);
B := (1/2)*subs(B = 2*A, B);
B(1,1):=1;
A;

For remainder of division of a (multivariable) polynomial to several polynomials at a same time one can use NormalForm in Maple. It is easy to write a procedure to also show the division but I wonder if there is any determined command such as NormalForm for this aim?

Previous year I was using Maple 2015 and I had a procedure in which I had used

A := Array((1 .. 3)$3);

And similar use of $. This year I'm using Maple 2016. Now I came back to my old procedure but Maple doesn't compile the procedure anymore and instead shows

Error, `$` unexpected
What is the problem? Is something changed in new version of Maple?

Why I use Array and $ is my old question here http://www.mapleprimes.com/questions/210628-Undefined-For-Loop-Bound which was fine before.

I want to use while in proc but Maple shows an error saying

"Error, (in exa) illegal use of a formal parameter"

When I click on it, as usual it says "There is no help page available for this error". I tried a very simple example of while which you can see it below and it again shows same error. The while works well but when I put it inside of a procedure it makes an error. Note: the following example is just an example, this is not what I'm doing so please don't reply this while proc is not giving anything. My question is how can I use a while in procedure without encountering the above error.

i := 10;
while i > 1 do
if i mod 2 = 0 then i := i/2; else i := i+1; end if;
end do;

Now with proc

exa := proc (i::integer)::integer;
while 1 < i do
if i mod 2 = 0 then i :=i/2; else i := i+1; end if
end do; 
end proc;

exa(10);

"Error, (in exa) illegal use of a formal parameter"