Negligible terms in polynomials



> op(I[1])=I, args(I[1])=[1]. So I[1] contains I, as an operator.

Ok.
> You can try something like
>
> freeof_var (e, [x]) := block ([v : listofvars(e)],
>   not apply("or", map (lambda([xx], member(xx,v)), x))
> )$
>
> freeof_var (a[1] + b[2] + c[3], a,b,c) => true
> freeof_var (a[1] + b[2] + c[3], a[1],b,c) => false
> freeof (a,b,c, a[1] + b[2] + c[3]) => false

Thank you again, this is what I needed!
Stefano