Editing Time hierarchy theorem (section)

==Background==
Both theorems use the notion of a [[constructible function|time-constructible function]]. A [[function (mathematics)|function]] <math>f:\mathbb{N}\rightarrow\mathbb{N}</math> is time-constructible if there exists a deterministic [[Turing machine]] such that for every <math>n\in\mathbb{N}</math>, if the machine is started with an input of ''n'' ones, it will halt after precisely ''f''(''n'') steps. All [[polynomial]]s with non-negative integer coefficients are time-constructible, as are exponential functions such as 2<sup>''n''</sup>.