Jip J. Dekker
f2a1c4e389
git-subtree-dir: software/mza git-subtree-split: f970a59b177c13ca3dd8aaef8cc6681d83b7e813
28 lines
1.1 KiB
MiniZinc
28 lines
1.1 KiB
MiniZinc
%-----------------------------------------------------------------------------%
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% Constrains two arrays of int variables to represent inverse functions.
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% All the values in each array must be within the index set of the other array.
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%
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% Linear version.
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%-----------------------------------------------------------------------------%
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% include "domain_encodings.mzn";
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% predicate inverse(array[int] of var int: f, array[int] of var int: g) =
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% let {
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% array[int,int] of var 0..1: map_f = eq_encode(f);
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% array[int,int] of var 0..1: map_g = eq_encode(g);
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% } in forall (i in index_set(f), j in index_set(g)) (map_f[i,j] = map_g[j,i]);
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%-----------------------------------------------------------------------------%
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%% Now copying the std version, seems a little faster on vrp-s2-v2-c7_vrp-v2-c7_det_ADAPT_1_INVERSE.mzn
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predicate fzn_inverse(array[int] of var int: f,
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array[int] of var int: invf) =
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forall(i in index_set(f)) ( f[i] in index_set(invf) ) /\
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forall(j in index_set(invf)) ( invf[j] in index_set(f) ) /\
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forall(i in index_set(f), j in index_set(invf)) (
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((j == f[i]) <-> (i == invf[j]))
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);
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