* rlim_floatX come from applying a technique derived from [SAS 07] onto a small floating-point reactive program taken from an industrial application

reactive 
rlim_float1:
7.3s, 50 MiB RAM

rlim_float2:
6.7s, 32 MiB RAM

* rlim_nofloat is the same as rlim_float1 but much simpler (the problem from whence it comes does not attempt to model floating-point)

* blowup5 and prsb23 come from the LIRA folks

* period9: the original period9 is a true universally quantified formula
  coming from Alain Colmerauer, An introduction to Prolog III. Communications of  the ACM. 33(7), 70-90, July 1990, p.79

  The _constraint? variants progressively relax constraints.
