About CTM The following Alice ML code is derived from the examples provided in the book:
"Concepts, Techniques, and Models of Computer Programming" by Peter Van Roy and Seif Haridi.
http://www2.info.ucl.ac.be/people/PVR/book.html

 (* CTM Chapter #12 Examples in Alice ML *) import structure Space from "x-alice:/lib/gecode/Space" import structure FS from "x-alice:/lib/gecode/FS" import structure FD from "x-alice:/lib/gecode/FD" import structure Search from "x-alice:/lib/gecode/Search" import structure Linear from "x-alice:/lib/gecode/Linear" import structure Explorer from "x-alice:/lib/tools/Explorer"; (* syntactic sugar for solutions using promises/futures *) open Linear open Promise open Future infix 3 ?= val op?= = fulfill val ? = future (* convert term to intvar *) fun term2intvar (FD(x)) = x | term2intvar _ = raise Domain (* convert int to intvar *) fun int2intvar (sp, x) = FD.intvar(sp, #[(x,x)]) (* 12.1.2 Propagate-and-search - Calculating with partial information *) fun partial sp = let val x = fdterm(sp, [90 `# 110]) val y = fdterm(sp, [48 `# 53]) val a = fdterm(sp, [0 `# 10000]) in (* Alice currently only supports linear expressions. Will be generalized for non-linear expressions in the next release. *) (* post (sp, x `* y `= a, FD.DOM); *) FD.mult (sp, term2intvar(x), term2intvar(y), term2intvar(a), FD.DOM); post (sp, a `> `4000, FD.DOM); post (sp, x `- `2 `* y `= `11, FD.DOM); branch (sp, #[a, x, y], FD.B_SIZE_MIN, FD.B_MIN); {a, x, y} end; Explorer.exploreAll partial; val sol = Search.searchAll partial (* another way to do the same thing *) fun partial2 sp = let val x = FD.intvar(sp, #[(90,110)]) val y = FD.intvar(sp, #[(48,53)]) val a = FD.intvar(sp, #[(0,10000)]) in FD.mult (sp, x, y, a, FD.DOM); post (sp, FD(a) `> `4000, FD.DOM); post (sp, FD(x) `- `2 `* FD(y) `= `11, FD.DOM); FD.branch (sp, #[x, y], FD.B_SIZE_MIN, FD.B_MIN); {x,y} end; Explorer.exploreAll partial2; (* 12.1.4 Propagate-and-search - Executing the example *) fun rectangle sp = let val v as #[x, y] = fdtermVec (sp, 2, [0 `# 9]) val a = FD.intvar(sp, #[(0,10000)]) (* needed for workaround *) in (* post (sp, x `* y `= `24, FD.DOM); *) FD.mult (sp, term2intvar(x), term2intvar(y), a, FD.DOM); post (sp, FD(a) `= `24, FD.DOM); post (sp, x `+ y `= `10, FD.DOM); post (sp, x `< y, FD.DOM); branch (sp, #[x, y], FD.B_SIZE_MIN, FD.B_MIN); {x, y} end; Explorer.exploreAll rectangle; (* 12.2.1 Programming techniques - Calculting with partial information *) (* Note: this comes straight out of the Alice documentation *) fun money sp = let val v as #[s, e, n, d, m, o', r, y] = Linear.fdtermVec (sp, 8, [0 `# 9]) in distinct (sp, v, FD.BND); post (sp, s `<> `0, FD.BND); post (sp, m `<> `0, FD.BND); post (sp, `1000`*s `+ `100`*e `+ `10`*n `+ d `+ `1000`*m `+ `100`*o' `+ `10`*r `+ e `= `10000`*m `+ `1000`*o' `+ `100`*n `+ `10`*e `+ y, FD.BND); branch (sp, v, FD.B_SIZE_MIN, FD.B_MIN); {s,e,n,d,m,o',r,y} end; Explorer.exploreAll money; (* 12.2.2 Programming techniques - Palindrome products revisited *) fun palindrome sp = let val a = FD.intvar(sp, #[(0,999999)]) val b = FD.intvar(sp, #[(0,999)]) val c = FD.intvar(sp, #[(0,999)]) val x = FD.intvar(sp, #[(0,9)]) val y = FD.intvar(sp, #[(0,9)]) val z = FD.intvar(sp, #[(0,9)]) in (* post (sp, FD(a) `= FD(b) `* FD(c), FD.DOM); *) FD.mult (sp, b, c, a, FD.DOM); post (sp, FD(a) `= (FD(x) `* `100000) `+ (FD(y) `* `10000) `+ (FD(z) `* `1000) `+ (FD(z) `* `100) `+ (FD(y) `* `10) `+ FD(x), FD.DOM); post (sp, FD(a) `> `100000, FD.DOM); branch (sp, #[FD(x),FD(y),FD(z),FD(b),FD(c)], FD.B_SIZE_MIN, FD.B_MIN); {a,x,y} end; Explorer.exploreOne palindrome;

Chris Rathman / Chris.Rathman@tx.rr.com