Can't rely on arg_maxnP just yet.

This change breaks compatibility with mathcomp < 1.10.

There's now also a `findP` in ssreflect's seq library.

Vedant Chavda authored 4 years ago and Björn Brandenburg committed 4 years ago

change it to perm_big

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

File preemption.util is renamed and moved to
util.nondecreasing. The new util file can be used
in both the old Prosa and the new Prosa.