1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | language ESSENCE 1.3.0 $ Problem Equidistant Frequency Permutation Arrays $ $ Problem details available at http://www.csplib.org/Problems/prob055/ $ $ Essence model by Andrew Martin $ $ Licenced under CC-BY-4.0 : http://creativecommons.org/licenses/by/4.0/ given v : int (1..) given d : int (1..) given q : int (1..) given lam : int (1..) letting dSequnce be domain int (1..q*lam) letting dElement be domain int (1..q) find E : set ( size v) of matrix indexed by [dSequnce] of dElement $ each element in (1..q) must occur lambda times per sequence such that forAll m in E . forAll element : dElement . ( sum index : dSequnce . toInt (m[index] = element)) = lam $ each non-identical pair must be hamming distance d apart such that forAll seqA, seqB in E . seqA = seqB \/ ( sum index : dSequnce . toInt (seqA[index] != seqB[index])) = d |