Multigrade operator

In logic and mathematics, a multigrade operator $$\Omega$$ is a parametric operator with parameter k in the set N of non-negative integers.

The application of a multigrade operator $$\Omega$$ to a finite sequence of operands (x1, …, xk) is typically denoted with the parameter k left tacit, as the appropriate application is implicit in the number of operands listed. Thus $$\Omega$$(x1, …, xk) may be taken for $$\Omega$$k(x1, …, xk).