PlanetPhysics/Multigrade Operator

A multigrade operator $$\Omega$$ is a parametric operator with parameter $$k$$ in the set $$\mathbb{N}$$ of non-negative integers.

The application of a multigrade operator $$\Omega$$ to a finite sequence of operands $$(x_1, \ldots, x_k)$$ is typically denoted with the parameter $$k$$ left tacit, as the appropriate application is implicit in the number of operands listed. Thus $$\Omega(x_1, \ldots, x_k)$$ may be taken for $$\Omega_k(x_1, \ldots, x_k).$$