Hello, thank you for the reference, yes, that talks to me, in other words, some values of Gamma[a/b], Pi^(c/d), Exp[Pi*e/f] and 2^(p/q), a,b,c,d,e,f, p and q integers are well approximated by algebraic numbers, this is the point, this should be explored more isn't ? I am not certain that a table ? a compendium of values like that are all known ? Actualy, considering the simplest possible a,b,c,d,... what is the best example or the most striking evaluation that could exist ? Also, about a certain algorithm for denesting radicals, is there a solution to this ? this is a very difficult problem, mathematica is quite good for extracting these automatically but it does not solve the problem completely by far. I tried many times to solve this : niet, I do not see how it can be done. best regards, simon plouffe