{{short description|Model of computation in which all processes are time-reversible}}
'''Reversible computing''' is any [[model of computation]] where every step of the [[computational process|process]], to some extent, is [[time-reversible]]. InThis ameans modelthat, given the output of a computation, thatit's usespossible to perfectly reconstruct the input. In systems that [[deterministicTransition system|progress]] [[State transitionDeterministic system|transitionsdeterministically]] from one state of the abstract machine to another, a necessarykey conditionrequirement for reversibility is thata the[[injective function|one-to-one]] [[Binary relation|relationcorrespondence]] ofbetween theeach state and its successor. Reversible computing is considered an unconventional approach to computation and is closely linked to [[Mapquantum (mathematics)|mappingcomputing]], fromwhere statesthe toprinciples theirof successorsquantum mustmechanics beinherently ensure reversibility (as long as [[injectivequantum state]]s are not measured or "[[wave function collapse|one-to-onecollapse]][[wave function collapse|d]]").<ref Reversiblename="Williams">{{cite computingbook is|author=Williams a|first=Colin formP. of|title=Explorations in Quantum Computing |publisher=[[unconventionalSpringer computingScience+Business Media|Springer]]. |year=2011 |isbn=978-1-84628-887-6 |pages=25–29}}</ref>
Due to the [[Unitarity (physics)|unitarity]] of [[quantum mechanics]], [[quantum circuit]]s are reversible, as long as they do not "[[wave function collapse|collapse]]" the [[quantum state]]s on which they operate.<ref name="Williams">{{cite book |author=Williams |first=Colin P. |title=Explorations in Quantum Computing |publisher=[[Springer Science+Business Media|Springer]] |year=2011 |isbn=978-1-84628-887-6 |pages=25–29}}</ref>
==Reversibility<!--'Logical reversibility', 'Charge recovery logic', and 'Adiabatic computing' redirect here-->==
