Show that $lambda x.(left {x right }(x)neq 0)$ is not recursive.












1












$begingroup$



Show that $lambda x.(left {x right }(x)neq 0)$ is not recursive.




I am trying to show this relation is not recursive using a code number for this relation so that I can ultimately prove that the decision problem for $lambda zx.(left {z right }(x)=0)$ is recursively unsolvable.



If I let $e$ be a code number for $lambda x.(left {x right }(x)neq 0)$, does this form a contradiction by assuming $g(x) = left {x right }(x)$ is a total recursive function? I am not sure how to use code numbers for this kind of relation.










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  • 1




    $begingroup$
    You have to clarify whether ${x}(x) neq 0$ means (1) the computation ${x}(x)$ terminates and returns a non-zero result or (2) the computation ${x}(x)$ does not terminate with a zero result. With either reading, you can reduce the halting problem to this one.
    $endgroup$
    – Rob Arthan
    Dec 6 '18 at 19:07


















1












$begingroup$



Show that $lambda x.(left {x right }(x)neq 0)$ is not recursive.




I am trying to show this relation is not recursive using a code number for this relation so that I can ultimately prove that the decision problem for $lambda zx.(left {z right }(x)=0)$ is recursively unsolvable.



If I let $e$ be a code number for $lambda x.(left {x right }(x)neq 0)$, does this form a contradiction by assuming $g(x) = left {x right }(x)$ is a total recursive function? I am not sure how to use code numbers for this kind of relation.










share|cite|improve this question









$endgroup$








  • 1




    $begingroup$
    You have to clarify whether ${x}(x) neq 0$ means (1) the computation ${x}(x)$ terminates and returns a non-zero result or (2) the computation ${x}(x)$ does not terminate with a zero result. With either reading, you can reduce the halting problem to this one.
    $endgroup$
    – Rob Arthan
    Dec 6 '18 at 19:07
















1












1








1





$begingroup$



Show that $lambda x.(left {x right }(x)neq 0)$ is not recursive.




I am trying to show this relation is not recursive using a code number for this relation so that I can ultimately prove that the decision problem for $lambda zx.(left {z right }(x)=0)$ is recursively unsolvable.



If I let $e$ be a code number for $lambda x.(left {x right }(x)neq 0)$, does this form a contradiction by assuming $g(x) = left {x right }(x)$ is a total recursive function? I am not sure how to use code numbers for this kind of relation.










share|cite|improve this question









$endgroup$





Show that $lambda x.(left {x right }(x)neq 0)$ is not recursive.




I am trying to show this relation is not recursive using a code number for this relation so that I can ultimately prove that the decision problem for $lambda zx.(left {z right }(x)=0)$ is recursively unsolvable.



If I let $e$ be a code number for $lambda x.(left {x right }(x)neq 0)$, does this form a contradiction by assuming $g(x) = left {x right }(x)$ is a total recursive function? I am not sure how to use code numbers for this kind of relation.







logic recursion computability






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share|cite|improve this question










asked Dec 5 '18 at 1:36









numericalorangenumericalorange

1,735311




1,735311








  • 1




    $begingroup$
    You have to clarify whether ${x}(x) neq 0$ means (1) the computation ${x}(x)$ terminates and returns a non-zero result or (2) the computation ${x}(x)$ does not terminate with a zero result. With either reading, you can reduce the halting problem to this one.
    $endgroup$
    – Rob Arthan
    Dec 6 '18 at 19:07
















  • 1




    $begingroup$
    You have to clarify whether ${x}(x) neq 0$ means (1) the computation ${x}(x)$ terminates and returns a non-zero result or (2) the computation ${x}(x)$ does not terminate with a zero result. With either reading, you can reduce the halting problem to this one.
    $endgroup$
    – Rob Arthan
    Dec 6 '18 at 19:07










1




1




$begingroup$
You have to clarify whether ${x}(x) neq 0$ means (1) the computation ${x}(x)$ terminates and returns a non-zero result or (2) the computation ${x}(x)$ does not terminate with a zero result. With either reading, you can reduce the halting problem to this one.
$endgroup$
– Rob Arthan
Dec 6 '18 at 19:07






$begingroup$
You have to clarify whether ${x}(x) neq 0$ means (1) the computation ${x}(x)$ terminates and returns a non-zero result or (2) the computation ${x}(x)$ does not terminate with a zero result. With either reading, you can reduce the halting problem to this one.
$endgroup$
– Rob Arthan
Dec 6 '18 at 19:07












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