Hello friends,Like the potter who constantly puts the ball of clay back on the wheel, 
never satisfied with the result, I am retouching this page, 
always the same one but in constant evolution: worrying too much about a particular audience,
looking for, but apparently not succeeding in, the most fluid presentation, 
the most progressive, the most appropriate examples,
trying to avoid, but apparently not succeeding, grey areas and logical biases,
hoping not to bore the potential reader from the very first lines,
and his patience until the end of the document.Without your friendly attention I have little chance of succeeding.Thank you in advance.marty.alain_at_free.fr