Since the theorems of (PA + "there is a nonstandard number") are recursively enumerable, by the <br> [Low Basis Theorem](http://en.wikipedia.org/wiki/Low_basis_theorem), [WKL0](http://en.wikipedia.org/wiki/Reverse_mathematics#Weak_K.C3.B6nig.27s_lemma_WKL0)'s proof of the completeness theorem gives a nonstandard model of PA of [low degree](http://en.wikipedia.org/wiki/Low_(computability). After seeing Adam Day's [answer][1] to <br> [this question](https://mathoverflow.net/questions/29550/completeness-easiest-hardest-problems), I wonder "how easy" such a model could be to compute. <br> Can a low nonstandard model of PA be: <br> a) minimal <br> b) computably dominated <br> c) K-trivial <br> ? If it can be more than one of those, which can it be simultaneously? [1]: https://mathoverflow.net/questions/29550/completeness-easiest-hardest-problems/35566#35566