v1.01 --> v1.50
* Completed Chapter 7
* changed notation for non erasing reduction
* some minor errors have been corrected

v1.00 --> v1.01
* In Figure 4.7 (differential interaction nets), added reduction rules for contr
  vs coweak and cocontr vs weak which where missing (a heritage of generalized
  contraction cells...).
* Changed the terminology regarding the development theorem, separating the
  the nomenclature between finitenss (SN) and uniqueness (CR), to be more
  historically accurate.
* Proof of the argument subsitution lemma (8.9) rewritten almost from scratch,
  in a far more complete way.
* Bibliography corrected and updated.
* Corrected a bugged macro that was leaving annoying white spaces after many
  figures in display math.
* Other minor changes