Dear GoF,

After Allan's english revision, this is what I propose for a "version 2" in the arXiv. 

What I have done is 
a) Supressed "Introduction : Dual laws, shuffle, infiltration, Hoffmann." in the beginning of (sub)section 5.2 (Modified laws) as there is no need of "bla-bla" there.
b) Make precise that $q_t\in \{0,1\}$ (Foissy's remark) in formula (43) 
c) Make precise the ranges of that $q_c,q_s,q_t$ in proposition 6.2
d) Modified the title of section 7

These are minor changes but it makes the paper more accurate.

Your remarks/comments will be appreciated.

Best regards
Gérard