Provably total computable function
= Provably total computable function
For a theory of arithmetic $T$ and a program index $e$, the function $\varphi_e$ is provably total in $T$ when $T$ proves its canonical totality sentence
$$
\forall x\,\exists y\,\operatorname{Comp}(e,x,y).
$$
If $T$ is recursively axiomatized, the indices of its provably total functions form a computably enumerable set.