Based on, for example,
http://bisqwit.iki.fi/story/howto/openmp/#LoopNesting
I do not think that 144 threads would be created, but I am not sure how one would enable nested parallelism here, since we're not using those OpenMP pragma directives. Regarding minimum chunk size, it seems that is what ```gps.for_each_minimal_n = min_n;``` in [oc_omp.cc](https://github.com/opencog/opencog/blob/a55b7a24ed057e550d760c90940acb702c2443be/opencog/util/oc_omp.cc#L33) is for.