diff -r d59bea55db9b -r c445c931472f examples/crypto.mod
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/crypto.mod	Mon Dec 06 13:09:21 2010 +0100
@@ -0,0 +1,84 @@
+/* CRYPTO, a crypto-arithmetic puzzle */
+
+/* Written in GNU MathProg by Andrew Makhorin <mao@gnu.org> */
+
+/* This problem comes from the newsgroup rec.puzzle.
+   The numbers from 1 to 26 are assigned to the letters of the alphabet.
+   The numbers beside each word are the total of the values assigned to
+   the letters in the word (e.g. for LYRE: L, Y, R, E might be to equal
+   5, 9, 20 and 13, or any other combination that add up to 47).
+   Find the value of each letter under the equations:
+
+   BALLET  45     GLEE  66     POLKA      59     SONG     61
+   CELLO   43     JAZZ  58     QUARTET    50     SOPRANO  82
+   CONCERT 74     LYRE  47     SAXOPHONE 134     THEME    72
+   FLUTE   30     OBOE  53     SCALE      51     VIOLIN  100
+   FUGUE   50     OPERA 65     SOLO       37     WALTZ    34
+
+   Solution:
+   A, B,C, D, E,F, G, H, I, J, K,L,M, N, O, P,Q, R, S,T,U, V,W, X, Y, Z
+   5,13,9,16,20,4,24,21,25,17,23,2,8,12,10,19,7,11,15,3,1,26,6,22,14,18
+
+   Reference:
+   Koalog Constraint Solver <http://www.koalog.com/php/jcs.php>,
+   Simple problems, the crypto-arithmetic puzzle ALPHACIPHER. */
+
+set LETTERS :=
+{     'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
+      'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
+};
+/* set of letters */
+
+set VALUES := 1..card(LETTERS);
+/* set of values assigned to the letters */
+
+set WORDS;
+/* set of words */
+
+param total{word in WORDS};
+/* total[word] is the total of the values assigned to the letters in
+   the word */
+
+var x{i in LETTERS, j in VALUES}, binary;
+/* x[i,j] = 1 means that letter i is assigned value j */
+
+s.t. phi{i in LETTERS}: sum{j in VALUES} x[i,j] = 1;
+
+s.t. psi{j in VALUES}: sum{i in LETTERS} x[i,j] = 1;
+
+s.t. eqn{word in WORDS}: sum{k in 1..length(word), j in VALUES}
+      j * x[substr(word,k,1), j] = total[word];
+
+solve;
+
+printf{i in LETTERS} "  %s", i;
+printf "\n";
+
+printf{i in LETTERS} " %2d", sum{j in VALUES} j * x[i,j];
+printf "\n";
+
+data;
+
+param :  WORDS :   total :=
+         BALLET       45
+         CELLO        43
+         CONCERT      74
+         FLUTE        30
+         FUGUE        50
+         GLEE         66
+         JAZZ         58
+         LYRE         47
+         OBOE         53
+         OPERA        65
+         POLKA        59
+         QUARTET      50
+         SAXOPHONE   134
+         SCALE        51
+         SOLO         37
+         SONG         61
+         SOPRANO      82
+         THEME        72
+         VIOLIN      100
+         WALTZ        34 ;
+
+end;