LogSharp

Logical Programming in .NET

Still definitely a work in progress, but the goal is to have a .NET Standard library to have Prolog-like functionality. LogSharp will be more formal-logic-y than Prolog though, since instead of defining rules like functions, usage involves defining implications.

Setup

Do you have dotnet? Get it.

$ git clone https://github.com/jdaless/LogSharp.git
$ cd LogSharp/
$ dotnet build
$ dotnet test

A lot of the tests will fail, they're just there to measure progress.

Example

Prolog pulled and C# code is part of the unit tests.

Relationships

From here

Prolog In

likes(mary,food).
likes(mary,wine).
likes(john,wine).
likes(john,mary).

Prolog Console

?- likes(mary,food). 
true.
?- likes(john,wine). 
true.
?- likes(john,food). 
false.

C# In

World w = new World();
Rule likes = new Rule();
w.Add(likes["mary", "food"]);
w.Add(likes["mary", "wine"]);
w.Add(likes["john", "wine"]);
w.Add(likes["john", "mary"]);
Console.WriteLine(w.Query(likes["mary","food"]);
Console.WriteLine(w.Query(likes["john","wine"]);
Console.WriteLine(w.Query(likes["john","food"]);

C# Console

True
True
False

Abraham

From here

Prolog in

son(ishmael, abraham, mother_is_slave).
son(isaac, abraham, mother_is_free).
patriarch(abraham).
freeborn(P,S) :- patriarch(P), 
                 son(S,P,F),
                 eq(F,mother_is_free).

Prolog Console

?- freeborn(X,Y).
X = abraham,
Y = isaac.

C# In

World w = new World();
Rule son = new Rule();
Rule patriarch = new Rule();
Rule freeborn = new Rule();
w.Add(son["ishmael", "abraham", "mother_is_slave"]);
w.Add(son["isaac", "abraham", "mother_is_free"]);
w.Add(patriarch["abraham"]);
using(var p = new Variable())
using(var s = new Variable())
using(var f = new Variable())
{
    w.Add(freeborn[p,s] < 
        patriarch[p] ^ 
        son[s,p,f] ^ 
        Rule.Equality[f, "mother_is_free"]);
}
using(var x = new Variable())
using(var y = new Variable())
{
    w.Query(freeborn[x,y]);
    Console.WriteLine(x.OfType<string>().Single());
    Console.WriteLine(y.OfType<string>().Single());
}

C# Console

abraham
isaac