 The class \(\mathbf{REC}\)  consisting of the total functions which are members of the class of partial recursive functions (formed by closing the class \(\mathbf{PR}\)  under the unbounded minimization operation) is such that \(\mathbf{REC} = \mathbf{GR}\). (See  Section 2.2.1  and Odifreddi (1989, ch. I.2).)