Singular

One can not return (from a procedure) an object belonging to a ring which did not exist at the start of the procedure.
What you can do:
inside your procedure:
- create a ring inside the procedure
- create an object in this ring
- export the object (so it will not destroyed at the end of the procedure)
- return the ring
after the return:
- change into the returned ring
- access the object
see for an example: solve from solve.lib

I am writing a small procedure. I am defining a ring inside the procedure (depending upon the parameter to the proc). The some computations are done and then procedure returns objects in this ring. Here is a sample code:

[code] LIB "ring.lib";
int p = 7; // primality of p or prime power is checked beforehand.

proc mytest( int n )
{
ring Qz = (0,z),x,dp;
minpoly = rootofUnity( n );
poly i = z^(n-1);
return (i);
}
ring dummy;
mytest(7);
[/code]
I am getting the following [b]message[/b]:
[quote] ? ring change during procedure call test: dummy -> Qz (level 1)[/quote]
I also tried with `export Qz`, just before return, but doesnt help. Any solution?

Not sure if this is relevant: It seems the command `[b]test[/b]` is already defined!!!
[code]> test(4);
// ** Gerhard, use the option command
>
[/code]


-- VInay