Sergey Bozhko authored 3 years ago and Björn Brandenburg committed 3 years ago

* rename [step_function] to [unit_growth]
* restructure file

lemma [count_filter_fun] is equivalent to ssreflect's [size_filter]

Sergey Bozhko authored 3 years ago and Björn Brandenburg committed 3 years ago

Note that many files have changed; however, this is due to the fact that some of the lemmas in nat.v have been renamed or removed.

Move everything into the new namespace starting with 'prosa' rather
than the bland 'rt'.