Let f be a primitive recursive total function, and let A be the set of all n such that the value f(n) is 'new' in the sense of being different from f(m) for all m<n. Show that A is primitive recursive.(adsbygoogle = window.adsbygoogle || []).push({});

How in the world do I attack this problem? I am totally lost. Any help would be greatly appreciated. Thanks.

I know that to show a set is primitive recursive the characteristic function of the set must be primitive recursive. What in the world, however, would be a suitable characteristic function for this set described above?

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# Primitive recursive functions :mad:

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