Definition
Idealised Computational Model
An idealised computational model considers computations over the natural numbers, typically functions
or decision problems asking whether some
has a property . The model assumes unbounded but finite resources: each computation may use an arbitrarily large finite amount of time and memory, while the program itself must have a finite description.
Computation is deterministic: the program and input uniquely determine each subsequent step. No random bits or external source of entropy are available; pseudorandom sequences can be computed, but are fixed by their initial seed.
Other objects, such as real numbers, may be represented indirectly through natural-number computations, for example by generating successive digits of their representation.