clp

问题 I am writing a constraint solver in Prolog that implements a simple logical formula: "(alive(A) and animal(A)) iff (awake(A) or asleep(A))" . I found one way to implement it in Constraint Handling Rules, but it is much more verbose than the original formula: :- use_module(library(chr)). :- chr_constraint is_true/1. is_true(A) \ is_true(A) <=> true. is_true(alive(A)),is_true(animal(A)) ==> is_true(awake(A));is_true(asleep(A)). is_true(awake(A)) ==> is_true(animal(A)),is_true(alive(A)). is_true

问题 I am solving a scheduling task in SWI Prolog using the CLPFD library. Since it is the first time I solve something more serious than was the sendmory I probably need some good advices from more experienced users. Let me briefly describe the domain/the task. Domain I have a "calendar" for a month. Everyday there are 2 for the whole day, 2 for the whole night (long 12h service). There are also, only Mon-Fri 10 more workers for 8 hours (short service). The domain constraints are, obviously:

问题 This is the game I've managed to generate the problem with 4 colours and 4 cubes randomly mixed and following the colour scheme suggested in the link. So, the goal is to generate the possible solutions to the problem using clpfd . The main principle is basic, the same face for all 4 cubes must be different. Used all_different/2 on 4 lists, each of them containing the respective side of the "tower" composed by 4 faces. So far, so good. Now I must assure that the final result is a composition

问题 I am trying to run an executable file (a linear programming solver CLP.exe) from Python 3.5. Import subprocess exeFile = " C:\\MyPath\\CLP.exe" arg1 = "C:\\Temp\\LpModel.mps" arg2 = "-max" arg3 = " -dualSimplex" arg4 = " -printi all" arg5 = "-solution t solutionFile.txt" subprocess.check_output([exeFile, arg1, arg2, arg3, arg4, arg5], stderr=subprocess.STDOUT, shell=False) When I run the python file in Eclipse PyDev, I can see the results in Eclipse console. But, no solution results are saved

问题 Attribute variables permit to extend unification. The following is about arcane details of the interface. Let's cut right to the chase! In sicstus-prolog library(atts) provides predicates for using attributed variables. I think I get what the SICStus Prolog User's Manual page for library(atts) says, except for one detail about verify_attributes(-Var, +Value, -Goals) : [...] verify_attributes/3 is called before Var has actually been bound to Value. If it fails, the unification is deemed to

问题 There is a lot of hype around the dif/2 constraint, especially as a rescue for some non-declarativity of (\=)/2 and (\==)/2. This non-declarativity is often characterized as non-monotonicity and examples of non-communtativity are given. But what would be the means to test whether test cases involving dif/2 are commutative. Here is a meta explanation what I want to do: I make a commutativity test, and I want to probe that both variants give the same result: ?- A, B. -- versus -- ?- B, A. So