These examples are stored in files “COMEX/EX03/modifCS2D.rb”, “COMEX/EX03/modifCS2Db.rb”, “COMEX/EX03/modifCS2Dc.rb” and “COMEX/EX03/modifCS3D.rb” respectively. They correspond to the examples of directory “RUBY/EX09” described in section IV.2.4.5. The example “COMEX/EX03/modifCS2Db.rb” is also programmed in python in file “COMEX/EX03/modifCS2Db.py”. No remark is to be done about these examples.