public override Proposition Resolve(string[] key, SymbolIs[] state)
{
//Resolve child prepositions.
_fact1 = _fact1.Resolve(key, state);
_fact2 = _fact2.Resolve(key, state);
SymbolIs sol1 = _fact1.CheckSolvable(key, state);
SymbolIs sol2 = _fact2.CheckSolvable(key, state);
//If both are false resolve to Not-True, if either is true resolve to True.
if (sol1 == SymbolIs.False && sol2 == SymbolIs.False)
{
return(new Not(new True()));
}
else if (sol1 == SymbolIs.True || sol2 == SymbolIs.True)
{
return(new True());
}
else
{
//If one of the facts can be proved false, it can be removed from the logic.
if (sol1 == SymbolIs.False)
{
return(_fact2);
}
else if (sol2 == SymbolIs.False)
{
return(_fact1);
}
else
{
return(this);
}
}
}
/// <summary>
/// Find propositions that infer value
/// </summary>
/// <param name="value"></param>
/// <returns></returns>
public List <Proposition> FindReferal(Proposition value)
{
List <Proposition> Referals = new List <Proposition>();
// Check against each proposition in KB
foreach (Proposition item in _StartWorld._KnowledgeBase.Propostions)
{
// For a proposition that refers to value
if (item.getB() == value.getA())
{
bool beenThere = false;
// If found check that proposition has not already been used
foreach (Proposition past in pastProps)
{
if (past == item)
{
beenThere = true;
}
}
// If it hasn't. USE IT
if (!beenThere)
{
pastProps.Add(item);
Referals.Add(item);
}
}
}
return(Referals);
}
public Proposition TryInfer(bool?[] Arguements)
{
if (this.Single | !(Operation == Operations.Implication | Operation == Operations.Biconditional))
{
return(null);
}
Proposition CurrentProp = new Proposition();
if ((_ARef != null) && (_ARef.IsTrue(Arguements) == true))
{
if (_BRef != null)
{
return(_BRef);
}
else
{
CurrentProp.setA(_B);
return(CurrentProp);
}
}
else if (Arguements[0] == true && _ARef == null)
{
if (_BRef != null)
{
return(_BRef);
}
else
{
CurrentProp.setA(_B);
return(CurrentProp);
}
}
return(null);
}
private Proposition fringecases(String[] Prop)
{
if (Prop.Length == 1)
{
return(SetProp(Prop)); // single arguement prop no need to parse
}
else
{
int inferCount = 0;
int inferPos = 0;
for (int i = 0; i < Prop.Length; i++)
{
if (Prop[i].Contains("=>"))
{
inferCount++;
inferPos = i;
}
}
if (inferCount == 1)
{
Proposition CurrentProp = new Proposition();
string[] left = new string[inferPos]; //room for left of infer
string[] right = new string[Prop.Length - left.Length - 1]; // room for what is left minus infer sign
Array.Copy(Prop, 0, left, 0, left.Length);
Array.Copy(Prop, inferPos + 1, right, 0, right.Length);
CurrentProp = SetProp(left, Operations.Implication, right);
return(CurrentProp);
}
else
{
return(generateProp(Prop)); //multi arguement prop, everything bracketed properly
}
}
}
public override Proposition Resolve(string[] key, SymbolIs[] state)
{
//Resolve child prepositions.
_requirement = _requirement.Resolve(key, state);
_implication = _implication.Resolve(key, state);
SymbolIs solution = CheckSolvable(key, state);
if (solution == SymbolIs.True)
{
return(new True());
}
else if (solution == SymbolIs.False)
{
return(new Not(new True()));
}
else
{
//If the requirement [A in A=>B] is true, return the implication [B].
SymbolIs req = _requirement.CheckSolvable(key, state);
if (req == SymbolIs.True)
{
return(_implication);
}
else
{
return(this);
}
}
}
public World(Proposition[] Propositions, int amount_args)
{
Proposition[] Temp = new Proposition[Propositions.Length - 1];
Array.Copy(Propositions, Temp, Temp.Length);
_KnowledgeBase = new KnowledgeBase(Temp);
_Goal = Propositions[Propositions.Length - 1];
Arguments = new bool?[amount_args];
}
/// <summary>
/// Returns a array of parsed propositions as a Proposition[]
/// Goal prop is last one
/// </summary>
/// <param name="Propositions">Takes in a String[] of propostion in english, assumes last one is goal</param>
/// <returns></returns>
public Proposition[] ParseProps(string[] Propositions)
{
Proposition[] result = new Proposition[Propositions.Length];
for (int i = 0; i < Propositions.Length; i++)
{
string[] splitted = SplitString(Propositions[i]);
result[i] = fringecases(splitted);
}
return(result);
}
/// <summary> Simplify the rule using the specified knowledge. Returns true if the rule was changed. </summary>
public bool Resolve(string[] key, SymbolIs[] knowledge)
{
Proposition newRule = _rule.Resolve(key, knowledge);
if (newRule == _rule)
{
return(false);
}
_rule = newRule;
if (_rule is True)
{
_definesLiteral = true;
}
return(true);
}
private void GenerateLiteral(Proposition literalPrep)
{
if (literalPrep is Not)
{
_literalPrep = literalPrep;
_literalVal = new Literal(((Not)literalPrep).Symbol, true);
_definesLiteral = true;
}
else if (literalPrep is Symbol)
{
_literalPrep = literalPrep;
_literalVal = new Literal(((Symbol)literalPrep).ToString(), false);
_definesLiteral = true;
}
}
/// <summary>
/// Finds if value is a single original proposition from the test file
/// </summary>
/// <param name="value"></param>
/// <returns></returns>
public bool IsOriginal(Proposition value)
{
foreach (Proposition item in _StartWorld._KnowledgeBase.Propostions)
{
if (item.Single && (item.getA() == value.getA()))
{
if (item.ANotted)
{
return(false);
}
return(true);
}
}
return(false);
}
protected Proposition FindHornRule(List <string> elements)
{
Proposition totalRule = base.FindImplication(elements);
if (totalRule is Implies)
{
GenerateLiteral(((Implies)totalRule).Implication);
_definesLiteral = false;
return(((Implies)totalRule).Requirement);
}
else
{
GenerateLiteral(totalRule);
return(new True());
}
}
/// <summary>
///
/// </summary>
/// <param name="left"></param>
/// <param name="oper"></param>
/// <param name="right">If right is null make a single prop</param>
/// <returns></returns>
private Proposition SetProp(string[] left, Operations oper, string[] right)
{
Proposition returnProp = new Proposition();
if (left.Length == 1)
{
if (left[0][0] == '~') // "~A"
{
left[0] = left[0].Substring(1);
returnProp.ANotted = true;
}
returnProp.setA(String2Symbol(left[0]));
}
else
{
returnProp.setA(generateProp(left));
}
if (right != null) // multi argument prop
{
if (right.Length == 1)
{
if (right[0][0] == '~') // "~A"
{
right[0] = right[0].Substring(1);
returnProp.BNotted = true;
}
returnProp.setB(String2Symbol(right[0]));
}
else
{
returnProp.setB(generateProp(right));
}
returnProp.Operation = oper;
}
return(returnProp);
}
public override Proposition Resolve(string[] key, SymbolIs[] state)
{
//Resolve child prepositions.
_fact1 = _fact1.Resolve(key, state);
_fact2 = _fact2.Resolve(key, state);
SymbolIs sol1 = _fact1.CheckSolvable(key, state);
SymbolIs sol2 = _fact2.CheckSolvable(key, state);
//If the either fact is Unknown return this, otherwise resolve to True if they are the same, or false if they are different.
if (sol1 == sol2 && sol1 != SymbolIs.Unknown)
{
return(new True());
}
else if (sol1 != SymbolIs.Unknown && sol2 != SymbolIs.Unknown)
{
return(new Not(new True()));
}
else
{
return(this);
}
}
public void AddToKB(Proposition PTemp)
{
_Propostions.Add(PTemp);
}
public void setB(int B)
{
_BRef = null;
_B = B;
}
/*
* public bool[] Arguments
* {
* get
* {
* return Arguments;
* }
* set
* {
* // if (Arguments == null || value.Length != Arguments.Length)
* // throw new System.ArgumentException("Wrong size arguments array");
* Arguments = value;
* }
* } */
public World(KnowledgeBase KnowledgeBase, Proposition Goal)
{
_KnowledgeBase = KnowledgeBase;
_Goal = Goal;
}
public void AddToKB(Proposition PTemp)
{
_KnowledgeBase.AddToKB(PTemp);
}
public void setB(Proposition B)
{
_BRef = B;
_B = -1;
}
public void setA(int A)
{
_ARef = null;
_A = A;
}
private Proposition generateProp(string[] PropositionString)
{
Proposition CurrentProp = new Proposition();
if (PropositionString.Length == 3) // base case
{
return(SetProp(new[] { PropositionString[0] }, String2Operation(PropositionString[1]), new[] { PropositionString[2] }));
}
if (PropositionString.Length <= 3)
{
throw new System.ArgumentException("Less than 3 agruements in base case");
}
int ParenthesisCount = 0;
Operations[] possible_linkers = new Operations[2] {
Operations.NotSet, Operations.NotSet
}; // before & after the first ( and before and after the last )
int[] Parenthesist_pos = new int[2];
for (int i = 0; i < PropositionString.Length; i++) //find high level brakets, srtring together prop left to right
{
if (PropositionString[i].Contains("("))
{
if (ParenthesisCount == 0) // found the start of a top level braket
{
Parenthesist_pos[0] = i;
if (i > 0) // Dont go out of array bounds
{
try{ // see if there is a valid operation linker
possible_linkers[0] = String2Operation(PropositionString[i - 1]);
if (possible_linkers[0] == Operations.Negation) // if it is a not, look past it
{
if (i > 1)
{
possible_linkers[0] = String2Operation(PropositionString[i - 2]);
}
else
{
possible_linkers[0] = Operations.NotSet;
}
}
}
catch (System.ArgumentException)
{
throw new System.ArgumentException("An operation should always come before a opening bracket");
}
}
}
ParenthesisCount++;
}
else if (PropositionString[i] == ")")
{
ParenthesisCount--;
if (ParenthesisCount == 0) // found the end of a top level braket
{
Parenthesist_pos[1] = i;
if (Parenthesist_pos[0] == 0 && Parenthesist_pos[1] == PropositionString.Length - 1)// strip brackets if they are around the whole term
{
string[] stripbrackets = new string[PropositionString.Length - 2];
Array.Copy(PropositionString, 1, stripbrackets, 0, stripbrackets.Length);
return(generateProp(stripbrackets));
}
if (Parenthesist_pos[0] == 1 && Parenthesist_pos[1] == PropositionString.Length - 1 && PropositionString[0] == "~")// brackets around whole thing but the not
{
string[] stripbrackets = new string[PropositionString.Length - 3];
Array.Copy(PropositionString, 2, stripbrackets, 0, stripbrackets.Length);
CurrentProp = SetProp(stripbrackets);
CurrentProp.ANotted = true;
return(CurrentProp);
}
if (i < PropositionString.Length - 1) // Dont go out of array bounds
{
try{ // see if there is a valid operation linker
possible_linkers[1] = String2Operation(PropositionString[i + 1]);
}
catch (System.ArgumentException)
{
throw new System.ArgumentException("An operation should always come after a closing bracket");
}
}
if (possible_linkers[0] == Operations.NotSet && possible_linkers[1] == Operations.NotSet)
{
throw new System.ArgumentException("Parenthesis Or code error, no prop detected before or after highest lvl brakets");
}
// recurse - take high level brackets put it on one side of prop, put whats left on other side
if (possible_linkers[0] == Operations.NotSet) // if brakets are on left side
{
string[] left = new string[Parenthesist_pos[1] - Parenthesist_pos[0] - 1]; //room what is in brakets
string[] right = new string[PropositionString.Length - left.Length - 3]; // room for what is left (- 1 for prop symbol -2 for brakets )
Array.Copy(PropositionString, Parenthesist_pos[0] + 1, left, 0, left.Length); // put what is in brakets in left
Array.Copy(PropositionString, Parenthesist_pos[1] + 2, right, 0, right.Length); // put what is left in right
CurrentProp = SetProp(left, possible_linkers[1], right);
if (Parenthesist_pos[0] > 0 && PropositionString[Parenthesist_pos[0] - 1][0] == '~')
{
CurrentProp.ANotted = true;
}
return(CurrentProp);
}
if (possible_linkers[1] == Operations.NotSet) // if brakets are on right side
{
string[] right = new string[Parenthesist_pos[1] - Parenthesist_pos[0] - 1]; //room what is in brakets
string[] left = new string[PropositionString.Length - right.Length - 3]; // room for what is left (- 2 for prop & 0 indexed array)
Array.Copy(PropositionString, 0, left, 0, left.Length); // put what is in brakets in left
Array.Copy(PropositionString, Parenthesist_pos[0] + 1, right, 0, right.Length); // put what is left in right
CurrentProp = SetProp(left, possible_linkers[0], right);
if (Parenthesist_pos[0] > 0 && PropositionString[Parenthesist_pos[0] - 1][0] == '~')
{
CurrentProp.BNotted = true;
}
return(CurrentProp);
}
}
if (ParenthesisCount < 0)
{
throw new System.ArgumentException("Too many closing brackets in Prop");
}
}
if (i == PropositionString.Length - 1 && ParenthesisCount != 0)
{
throw new System.ArgumentException("Miss matched Parenthesis in Propostion");
}
}
if (ParenthesisCount != 0)
{
throw new System.ArgumentException("Miss matched Parenthesis in Propostion (Code logic error)");
}
//If there are no brakets continue bellow
string[] rightprop = new string[PropositionString.Length - 2];
Array.Copy(PropositionString, 2, rightprop, 0, PropositionString.Length - 2);
CurrentProp = SetProp(new[] { PropositionString[0] }, String2Operation(PropositionString[1]), rightprop);
return(CurrentProp);
}
public Not(Proposition fact)
{
_fact = fact;
}
public void setA(Proposition A)
{
_ARef = A;
_A = -1;
}
public Or(Proposition fact1, Proposition fact2)
{
_fact1 = fact1;
_fact2 = fact2;
}
public BiConditional(Proposition fact1, Proposition fact2)
{
_fact1 = fact1;
_fact2 = fact2;
}
/// <summary>
/// A DFS to find paths that return only original propositions from the test file
/// </summary>
/// <param name="value"></param>
/// <returns></returns>
public List <int> Chain(Proposition value)
{
List <int> result = new List <int>();
List <Proposition> temp;
// Singualr Proposition
if (value.Single)
{
if (IsOriginal(value))
{
result = new List <int>();
result.Add(value.getA());
return(result);
}
else if ((temp = FindReferal(value)).Count != 0)
{
foreach (Proposition Refered in temp)
{
result = Chain(Refered);
if (result.Count != 0)
{
result.Add(Refered.getB());
}
}
}
else
{
return(new List <int>());
}
}
// Implication Proposition
else if (value.Operation == Operations.Implication)
{
if (value.IsAref())
{
result = Chain(value.getARef());
}
else if (IsOriginal(value.getA()))
{
result = new List <int>();
result.Add(value.getA());
return(result);
}
else if ((temp = FindReferal(value.getA())).Count != 0)
{
foreach (Proposition Refered in temp)
{
result = Chain(Refered);
if (result.Count != 0)
{
result.Add(Refered.getB());
}
}
return(result);
}
else
{
return(new List <int>());
}
}
// And Proposition
else if (value.Operation == Operations.Conjunction)
{
List <int> MiniListA = new List <int>();
List <int> MiniListB = new List <int>();
// Find A referals
// if a ref
if (value.IsAref())
{
MiniListA = Chain(value.getARef());
}
// If A is a Singular Original
else if (IsOriginal(value.getA()))
{
MiniListA = new List <int>();
MiniListA.Add(value.getA());
}
// Else find referals of A
else if ((temp = FindReferal(value.getA())).Count != 0)
{
foreach (Proposition Refered in temp)
{
MiniListA = Chain(Refered);
if (MiniListA.Count() != 0)
{
MiniListA.Add(value.getA());
}
}
}
// If no referals
else
{
return(new List <int>());
}
// Find B referals
// If b ref
if (value.IsBref())
{
MiniListB = Chain(value.getBRef());
}
// If B is a Singular Original
else if (IsOriginal(value.getB()))
{
MiniListB = new List <int>();
MiniListB.Add(value.getB());
}
// else find referals
else if ((temp = FindReferal(value.getB())).Count != 0)
{
foreach (Proposition Refered in temp)
{
MiniListB = Chain(Refered);
if (MiniListB.Count() != 0)
{
MiniListB.Add(value.getB());
}
}
}
// If no referals
else
{
return(new List <int>());
}
// If nether null then add together and return
if ((MiniListA.Count() == 0) || (MiniListB.Count() == 0))
{
return(new List <int>());
}
result = new List <int>();
result.AddRange(MiniListA);
result.AddRange(MiniListB);
return(result);
}
// OR Proposition
else if (value.Operation == Operations.Disjunction)
{
List <int> MiniListA = new List <int>();
List <int> MiniListB = new List <int>();
// Find referals of A
// If A ref
if (value.IsAref())
{
MiniListA = Chain(value.getARef());
}
// If A is a Singular Original
else if (IsOriginal(value.getA()))
{
MiniListA = new List <int>();
MiniListA.Add(value.getA());
}
// Else find referals
else if ((temp = FindReferal(value.getA())).Count != 0)
{
foreach (Proposition Refered in temp)
{
MiniListA = Chain(Refered);
if (MiniListA.Count() != 0)
{
MiniListA.Add(value.getA());
}
}
}
//Find referals of B
// If B ref
if (MiniListA.Count() == 0)
{
if (value.IsBref())
{
MiniListB = Chain(value.getBRef());
}
// If B is a Singular Original
else if (IsOriginal(value.getB()))
{
MiniListB = new List <int>();
MiniListB.Add(value.getB());
}
// Else find referals
else if ((temp = FindReferal(value.getB())).Count != 0)
{
foreach (Proposition Refered in temp)
{
MiniListB = Chain(Refered);
if (MiniListB.Count() != 0)
{
MiniListB.Add(value.getB());
}
}
}
}
// If both empty, return empty
if (MiniListA.Count == 0 && MiniListB.Count == 0)
{
return(new List <int>());
}
//else add together and return
result = new List <int>();
result.AddRange(MiniListA);
result.AddRange(MiniListB);
return(result);
}
// Finally return the result
return(result);
}
public Rule(string ruleAsText)
{
debugTextVersion = ruleAsText.Trim();
_rule = FindImplication(GenerateElements(debugTextVersion));
}
public Implies(Proposition requirement, Proposition implication)
{
_requirement = requirement;
_implication = implication;
}