public void Constructor_ParsedPropositionGiven_ShouldResultInNegatedPropositionAsRoot()
{
// Arrange
Proposition randomValidProposition = PropositionGenerator.GetRandomProposition();
SemanticTableaux semanticTableaux = new SemanticTableaux(randomValidProposition);
// Act
Proposition root = semanticTableaux.Proposition;
// Assert
root.Should().Be(randomValidProposition, "Because the original expression is being evaluated");
}
public void CreateContradictionFromProposition_ValidPropositionGiven_ExpectedAllAssignmentsToResultInFalse(bool truthValue)
{
// Arrange
Proposition randomProposition = PropositionGenerator.GetRandomProposition();
Proposition contradiction = PropositionGenerator.CreateContradictionFromProposition(randomProposition);
contradiction.TruthValue = truthValue;
// Act
bool actualTruthValue = contradiction.Calculate();
// Assert
actualTruthValue.Should().BeFalse("Because a contradiction should always evaluate to false");
}
public void CreateTautologyFromProposition_ValidPropositionGiven_ExpectedAllAssignmentsToResultInTrue(bool truthValue)
{
// Arrange
Proposition randomProposition = PropositionGenerator.GetRandomProposition();
Proposition tautology = PropositionGenerator.CreateTautologyFromProposition(randomProposition);
tautology.TruthValue = truthValue;
// Act
bool actualTruthValue = tautology.Calculate();
// Assert
actualTruthValue.Should().BeTrue("Because a tautology should always evaluate to true");
}
public void CreateDisjunctiveNormalForm_IndividualPropositionGiven_ExpectedIndividualPropositionReturned()
{
// Arrange
Proposition originalProposition = PropositionGenerator.GetRandomProposition();
TruthTable tt = new TruthTable(originalProposition);
TruthTable simplifiedTt = tt.Simplify();
// Act
Proposition dnf = tt.CreateDisjunctiveNormalForm();
Proposition simplifiedDnf = simplifiedTt.CreateDisjunctiveNormalForm();
// Assert
dnf.Should().BeEquivalentTo(originalProposition, "Because the disjunctive normal of a proposition literal is the literal itself");
simplifiedDnf.Should().BeEquivalentTo(originalProposition, "Because a literal can not be simplified any further and should result in the literal itself.");
}
public void Copy_CopyQuantifier_ExpectedEqualsToBeTrueButDifferentReferences()
{
// Arrange
Quantifier quantifier = GetQuantifier();
quantifier.LeftSuccessor = PropositionGenerator.GetRandomProposition();
// Act
Proposition copy = quantifier.Copy();
bool equal = quantifier.Equals(copy);
bool sameReference = quantifier == copy;
// Assert
equal.Should().BeTrue("Because the quantifier is copied");
sameReference.Should().BeFalse("Since copies should be different references");
}
public void IsClosed_TestIsClosedWhenChildNullAndNoContradictionInSet_ExpectedFalseReturned()
{
// Arrange
HashSet <Proposition> propositionSet = new HashSet <Proposition>()
{
PropositionGenerator.GetRandomProposition(),
PropositionGenerator.GetRandomProposition()
};
SemanticTableauxElement alphaRuleElement = new SemanticTableauxElement(propositionSet);
// Act
bool isBranchClosed = alphaRuleElement.IsClosed();
// Assert
isBranchClosed.Should().BeFalse("Because the tableaux element has no contradiction and no children, thus was not closed.");
}
private List <Proposition> generateXPropositionVariables(int x)
{
Proposition previous = null;
Proposition newProposition = null;
List <Proposition> propositions = new List <Proposition>();
while (propositions.Count < x)
{
previous = newProposition;
newProposition = PropositionGenerator.GetRandomProposition();
if (previous != null && !newProposition.Data.Equals(previous.Data))
{
propositions.Add(newProposition);
}
}
return(propositions);
}