unbounded search operator

2024-03-11

let , where is some polynomial with integer coefficients and where denotes "the least such that ".

if is a partial computable function, and

then is a partial computable function.

let be a PRC class, if belongs to , then so do the functions

and

the sum of functions can be used to construct the quantifier in primitive recursive predicates, give a predicate in some PRC class, it follows form the theorem that is in PRC aswell because it simply can be represented by the function eq-unbounded-search-op-sum. the same goes for the predicate which can be represented by the function eq-unbounded-search-op-prod.

let belong to some given PRC class . then by the-iter-ops the function

also belongs to .
(taken from Martin Davis, Ron Sigal, Elaine J. Weyuker, 1994 chapter 3.7 minimalization)

if belongs to some PRC class and , then also belongs to .

the operation is called bounded minimalization.