Talk:Primitive recursive function: Difference between revisions

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:''In fact, it is difficult to devise a '''total''' computable function that is not primitive recursive.''
--[[User:Jobu0101|Jobu0101]] ([[User talk:Jobu0101|talk]]) 11:13, 22 April 2015 (UTC)
 
:: The ackerman function is such a function. It is not primitive recursive. And its total. The proof goes usually by majorization. In terms of LOOP/WHILE one would show that for every program with n-LOOPs there is some ackerman function invocation, that grows more than the n-LOOPs program. By this majorization, one can show that the ackeman function cannot be implemented by a LOOP-program.
:Good point. I changed "computable" to "total recursive" in that sentence. [[User:JRSpriggs|JRSpriggs]] ([[User talk:JRSpriggs|talk]]) 04:56, 23 April 2015 (UTC)
 
:: BTW: The ackerman function is such a function. It is not primitive recursive. And its total. The proof goes usually by majorization. In terms of LOOP/WHILE one would show that for every program with n-LOOPs there is some ackerman function invocation, that grows more than the n-LOOPs program. By this majorization, one can show that the ackeman function cannot be implemented by a LOOP-program.
 
:: But you are not alone, David Hilbert believed the same, until the discovery of the [[Ackermann function]] showed the contrary.
 
:Good point. I changed "computable" to "total recursive" in that sentence.:: [[User:JRSpriggsJanburse|JRSpriggsJan Burse]] ([[User talk:JRSpriggsJanburse|talk]]) 0413:5640, 2328 AprilFebruary 20152024 (UTC)
 
== Floop issue. ==