 Computational problem in the SCI hierarchy

A computational problem is a quadruple $(\Xi ,\Omega ,\mathcal{M},\Lambda )$: the primary set $\Omega$ contains the inputs, $\Lambda$ is the family of permitted evaluation functions, $(\mathcal{M},d)$ is the output metric space, and $\Xi :\Omega \to \mathcal{M}$ is the problem function.