First, is patmatch command is the main Maple command for doing pattern matching on expressions?  

I trying to understand how it works, but failing on the most basic expressions. 2 basic questions

1)patmatch( x^n/y^n,  x∷symbol^n::symbol /  y::symbol^n::symbol);
                               false

It did not like that I told it x::symbol in the above. Why? But when I remove ::symbol it works

patmatch(x^n/y^n,x^n::symbol/y^n::symbol);
                   true

But when I do "whattype(x);" Maple replies saying it is "symbol"

2)Trying to match x^2/y^2, not having any luck
patmatch(x^2/y^2,x^n::nonunit(integer)/y^n::nonunit(integer));
                        false

patmatch(x^2/y^2,x^n::integer/y^n::integer);
                         false

How to match x^2/y^2? Why the above fail? 

I learn better by examples. Is there a place where one can look at many examples using patmatch? 

The help page have only few examples, and the link to the page called "examples,patmatch" does not help either with few examples and many are the same as the other page.  I tried to run it using 

infolevel[all]:=5:
printlevel:=10:

To see if I can figure what is wrong, but did not understand any of the code printed.

Compare this to Mathematica, where pattern matching there has hundreds of examples and detailed tutorials just on this one subject.

Given an expression such as (x^2+1)*y^3*exp(-x-y), how to "factor" it to product of the two functions, one in x only and the other in y only. These products in this example are

                  exp(-x)*(1+x^2)

and

                 exp(-y)*y^3

For reference, this was also asked at Mathematica site here

addition:

Is it possible to obtain these separated products in a list or a set to make them easier to get hold of after the call? something like

   myFactor(  (x^2+1)*y^3*exp(-x-y) , {x , y} )

will return

    { exp(-x)*(1+x^2) , exp(-y)*y^3 }

This is current test cases

funcs:=[
   arcsin(x)/(sqrt(1-x^2)*y^2),
   x*y,
   x^2+x^2*y,
   2*x+1,
   cos(2*x),
   y,
   (x-1)/y,
   ln(1+y^2),
   1-x+y^2-x*y^2,
   x^2+x^3*y,
   1/(x+y),
   (1+sqrt(x))/(1+sqrt(y)),
   (1-x^2+y^2-x^2*y^2)/x^2,
   2*x*y^2+3*x^2*y^2,
   3*exp(2*x)+2*y,
   (5*sqrt(x)-y)/x,
   2*x*y+3*x^2*exp(x^2),
   sqrt(1+x+y^2),
   1,
   1+x*y,
   -y+4*x^3*y,
   exp(x^2)+2*x*y,
   -(y-exp(x))/(x-2),
   arcsin(x)/((1-x^2)*y^2),
   -(y-exp(x))/(x-2),
   -y+4*x^3*y,
   (x^2*y+y)*y^3*exp(-x-y+1)*3^(-x-y)*sqrt(x^2*y-y),
    sqrt(1-y^2)/x,
    sqrt(1-y^2)/(2*sqrt(x)),
    sqrt(1-y^2)
];

This functions checks if expression is product separable or not

is_separable:=proc(f,x,y)
  #checks if f(x,y) is separable to X(x)*Y(y) or not
  #but do not do the separation. The separation is done by
  #another function I have

  if diff(simplify(diff( simplify(ln(f)),x)),y) = 0 then
     return(true);
  else
     return(false);
  fi;
end proc:

it used as

for z in funcs do
   is_separable(z,x,y);
od;

I just found that Maple 17 and Maple 16 do not have the option "output=string" in the latex command.

And I need a way to convert the Latex generated to the screen to a string and save it to a variable like I can do with Maple 2017

Here is an example. In current Maple 2017 this works

result_of_int:=int((-5+3*x)^2/(2*x-1)^(7/2),x):
my_latex:= latex(result_of_int,output=string);

But in Maple 16, it gives an error

If I remove the output, then the result is not string.

How to capture the above output which is on the screen and save it as string in a variable?

I do not want to send the output to a file as is. I need to first convert it to a string, and save
it to variable first.

Would someone be able to explain this strange output?

restart;
sol:=int(1/(x*sin(x)),x);
algsubs(x=t,sol);

How did Maple manage to obtain this? I tried tracing but it did not help me figure it out.  If it is of any help:

int(1/sin(x),x);

It seems algsubs got confused somewhere?

Maple 2017.2, windows.

Does Maple have build-in function, which when given an expression that depends on x and y, will separate it to a product of two functions, one that depedns on x only and the other that depends on y only?

The input mathematical expression is known to be seperable.

For example, If the input is

((3*y + y^2)*3*x)/(x + sin(x))

Then I'd the Maple function to take the above and return list or set of two parts  {(3*y + y^2)   ,     3*x/(x + sin(x) } (if it can't separate it, it can return null).

The API can be something as  

 f,g = find_product_functions(expression,[x,y])

Something like this is used on determining for example if RHS of first order ODE is separable in order to solve it more easily.  collect() does not really work for this. So Maple allready does this internally in its ODE solver when it checks if ODE is separable or not. But is the function available for users?