the command singular can return results with _Z or _N as it says in help

**The singular function may return expressions prefixed by _Z or _N, representing the integers and positive integers, respectively.**

But it changes these letters by adding different number at the end for each call., Yet they all mean the same thing, which is an integer:

singular(1/sin(x),x) {x = Pi*_Z1} singular(x/sin(x),x) {x = Pi*_Z2} singular(x^2/sin(x),x) {x = Pi*_Z3}

This makes it little hard when I try to make union of these results to only keep the unique singular points, since they are different symbols, yet they are really the same: integer times Pi.

Is there an option to tell Maple to use _Z for everything? And not keep adding new numbers each time it is called?

May be clear some internal memory table after each call? Otherwise, I have to add more code to parse all these results and convert all **_Znnn** to just **_Z** if it is there in each result, after each call is made.

Same issue for **_N**

**Update**

Additional example to try/test against

expr:=1/(sin(x)*cos(x)*tan(x)); s := singular(expr, x); expr:=1/((x-1)*sin(x)); s := singular(expr, x); expr:=1/(sin(x)*cos(x-Pi/3)*tan(x)); s := singular(expr, x);

In all the outputs above, I'd like to have same **_Z **show up. This will make it easier for postprocessing later on. Best solution will be to tell Maple itself not to change _Z if possible, otherwise one will need to add code to do this afterwords for all possible cases.