guyhaw wrote:The 'sticking point' is having the right code to generate 5-1 index-schemes, including code for '(4) men of a kind'.
I don't know how generic Nalimov's 'like men' code is.
Marc B is the expert on indexing-schemes as on all other things, and has I believe collaborated with Eugene Nalimov on the 3-3p index-scheme. he understands the indexing regimes of Nalimov, FEG and Konoval, and may have a generic index-scheme in his GTBGEN code.
So my recommendation is to wait for Marc B to advise us. Oh, my other one is to generate 5-1(p) EGTs to DTZ, not DTM.
g
I had understood that EN would use this formula to trasform positions of n like men into a subindex:
subindex = X1 + (X2, 2) + (X3, 3) + ... + (Xn, n)
where X1, X2, X3, ... , Xn are the positions of the n like men from 0 to 63 with the condition X1 < X2 < X3 < ... < Xn, while (X2, 2), (X3, 3), ... , (Xn, n) are binomial coefficients, with the
convention that (a, b) = 0 if a < b.
But this formula would preclude the possibility of discarding from the file the positions where a check is given by a man close to the opponent king.
A little more complicate and less fast is the inversion process, which corresponds to solve a
diophantine equation in N integer variables.
guido
