Editing Kleene's recursion theorem (section)

=== Comparison to Rogers's theorem ===
Kleene's second recursion theorem and Rogers's theorem can both be proved, rather simply, from each other.{{sfn|Jones|1997|pp=229-30}} However, a direct proof of Kleene's theorem{{sfn|Kleene|1952|pp=352-3}} does not make use of a universal program, which means that the theorem holds for certain subrecursive programming systems that do not have a universal program.