public void ApplySubMap(SubstitutionMap subMap)
{
foreach (var atom in Atoms)
{
atom.ApplySubMap(subMap);
}
}
public Term(Term term)
{
Id = term.Id;
ParentA = term.ParentA;
ParentB = term.ParentB;
Atoms = new List <Atom>();
foreach (var atom in term.Atoms)
{
Atoms.Add(new Atom(atom));
}
SubMap = new SubstitutionMap(term.SubMap);
FromGoal = term.FromGoal;
}
private static SubstitutionMap Unify(Atom a, Atom b, SubstitutionMap subMap)
{
var output = new SubstitutionMap(subMap);
if (a.Name != b.Name || a.Arguments.Count != b.Arguments.Count)
{
output.Failure = true;
return(output);
}
var atomA = new Atom(a);
var atomB = new Atom(b);
atomA.ApplySubMap(output);
atomB.ApplySubMap(output);
var disagreement = false;
for (var i = 0; i < atomA.Arguments.Count; i++)
{
var argA = atomA.Arguments[i];
var argB = atomB.Arguments[i];
if (argA.EqualTo(argB))
{
continue;
}
disagreement = true;
if (argA.CanMapTo(argB))
{
subMap.Add(argA, argB);
var newOutput = Unify(atomA, atomB, subMap);
newOutput.Changed = true;
return(newOutput);
}
if (argB.CanMapTo(argA))
{
subMap.Add(argB, argA);
var newOutput = Unify(atomA, atomB, subMap);
newOutput.Changed = true;
return(newOutput);
}
break;
}
if (disagreement)
{
output.Failure = true;
}
return(output);
}
public SubstitutionMap(SubstitutionMap subMap)
{
if (subMap._vars.Count > 0)
{
_vars = new Dictionary <Argument, Argument>();
foreach (var key in subMap.Keys)
{
_vars.Add(new Argument(key), new Argument(subMap.Get(key)));
}
}
else
{
_vars = new Dictionary <Argument, Argument>();
}
}
public bool EqualTo(SubstitutionMap subMap)
{
if (Keys.Count() != subMap.Keys.Count())
{
return(false);
}
foreach (var mySubs in _vars)
{
if (!subMap.ContainsKey(mySubs.Key))
{
return(false);
}
if (!subMap.Get(mySubs.Key).EqualTo(Get(mySubs.Key)))
{
return(false);
}
}
return(true);
}
private static SubstitutionMap UnifySubMap(SubstitutionMap subMapA, SubstitutionMap subMapB)
{
var output = new SubstitutionMap();
foreach (var keyA in subMapA.Keys)
{
if (subMapB.ContainsKey(keyA))
{
output.Failure = true;
return(output);
}
output.Add(keyA, subMapA.Get(keyA));
}
foreach (var keyB in subMapB.Keys)
{
output.Add(keyB, subMapB.Get(keyB));
}
return(output);
}
public void InnerLoop(List <Argument> arguments, SubstitutionMap subMap)
{
foreach (var arg in arguments)
{
switch (arg.Type)
{
case ArgType.Constant:
continue;
case ArgType.Variable:
if (subMap.ContainsKey(arg))
{
var otherArg = subMap.Get(arg);
arg.Name = otherArg.Name;
arg.Type = otherArg.Type;
if (otherArg.Arguments != null && otherArg.Arguments.Count > 0)
{
arg.Arguments = new List <Argument>(otherArg.Arguments);
}
}
continue;
case ArgType.Function:
if (subMap.ContainsKey(arg))
{
var otherArg = new Argument(subMap.Get(arg));
arg.Name = otherArg.Name;
arg.Type = otherArg.Type;
arg.Arguments = new List <Argument>(otherArg.Arguments);
}
else
{
InnerLoop(arg.Arguments, subMap);
}
continue;
}
}
}
private static List <Atom> GetCombinedAtoms(Term a, Term b, SubstitutionMap subMap)
{
//apply combined submap to each term
var termA = new Term(a);
var termB = new Term(b);
termA.ApplySubMap(subMap);
termB.ApplySubMap(subMap);
var output = new List <Atom>();
//add all of term A's atoms if they check out
var allFailed = true;
foreach (var atomA in termA.Atoms)
{
var atomToAdd = atomA;
foreach (var atomB in termB.Atoms)
{
var unifyResult = Unify(atomA, atomB, subMap);
if (unifyResult.Failure)
{
continue;
}
allFailed = false;
if (unifyResult.Changed)
{
return(GetCombinedAtoms(termA, termB, unifyResult));
}
atomToAdd = new Atom
{
Name = "",
Arguments = null,
IsBool = true,
Truthfulness = (atomA.Truthfulness == atomB.Truthfulness)
};
break;
}
output.Add(atomToAdd);
if (atomToAdd.IsBool && atomToAdd.Truthfulness)
{
return(output);
}
}
//add all of term B's atoms if they check out
foreach (var atomB in termB.Atoms)
{
var atomToAdd = atomB;
foreach (var atomA in termA.Atoms)
{
var unifyResult = Unify(atomB, atomA, subMap);
if (unifyResult.Failure)
{
continue;
}
allFailed = false;
if (unifyResult.Changed)
{
return(GetCombinedAtoms(termB, termA, unifyResult));
}
atomToAdd = new Atom
{
Name = "",
Arguments = null,
IsBool = true,
Truthfulness = (atomA.Truthfulness == atomB.Truthfulness)
};
break;
}
output.Add(atomToAdd);
if (atomToAdd.IsBool && atomToAdd.Truthfulness)
{
return(output);
}
}
if (allFailed)
{
return(new List <Atom> {
new Atom
{
IsBool = true,
Truthfulness = true
}
});
}
return(output);
}
public void ApplySubMap(SubstitutionMap subMap)
{
InnerLoop(Arguments, subMap);
}
private void Init()
{
Atoms = new List <Atom>();
SubMap = new SubstitutionMap();
}