Representing recursively enumerable languages by iterated deletion

Michael Domaratzki, Alexander Okhotin
2004 Theoretical Computer Science  
A characterization of the recursively enumerable languages in terms of the iterated deletion operation is given. This solves two open problems posed by Ito and Silva on the closure properties and decidability of iterated deletion.
doi:10.1016/j.tcs.2004.01.002 fatcat:jrf3wox24vb5lhmahnow2kqg6m