counts lines/tokens in Why3 files
distinguishes spec (logic declarations and annotations) and code
reports the ratio spec/code with command line option -f

example: why3wc -f examples/*.mlw
see why3wc --help for more details

note: why3wc assumes that input files are lexically well-formed
it also makes some approximations (switching from spec to code and
conversely is only done when there is a blank line in the middle)

(to be consistent with list.Sorted)

completed proof of mergesort_list (tail rec version of merge)

array.ArraySorted is now generic, with type and order relation parameters

In analogy to the equivalence lemmas for recursive function definitions,
the introduction rules of a (co)inductive predicate are output as proof
obligations in realization mode if syntax has been declared for the
predicate.