A reference model of computation \(\mathfrak{M}\) is chosen to represent algorithms. \(\mathfrak{M}\) is assumed to be a reasonable model in the sense that it accurately reflects the computational costs of carrying out the sorts of informally specified algorithms which are encountered in mathematical practice. The deterministic Turing machine model \(\mathfrak{T}\) is traditionally selected for this purpose. (See   Section 2.2   for further discussion of reasonable models and the justification of this choice.)