This patch was created using

  find -name *.v | xargs -L 1 awk -i inplace '{from = 0} /^From/{ from = 1; ever_from = 1} { if (from == 0 && seen == 0 && ever_from == 1) { print "Set Default Proof Using \"Type*\"."; seen = 1 } }1 '

and some minor manual editing

This fixes issue #46.

We need to change the core of X from ∅ to X to make elements of gset persistent.

I had to perform some renaming to avoid name clashes.

The new updates allow allocation fresh elements satisfying an arbitrary
proposition (for example, being even) instead of just not being in a given
finite set.

TODO: maybe also do this for finite maps (gmaps).

Also, add algebra/gset to _CoqProject.