public void Constructor_CreateUniversalQuantifierNoReplacementVariablesPresent_GammaRuleShouldNotBeAppliedNoChildrenGenerated()
{
// Arrange
char boundVariable = PropositionGenerator.GenerateBoundVariable();
List <char> boundVariables = new List <char>()
{
boundVariable
};
Predicate predicate = new Predicate(PropositionGenerator.GetRandomVariableLetter(), boundVariables);
UniversalQuantifier universalQuantifier = new UniversalQuantifier(boundVariable);
universalQuantifier.LeftSuccessor = predicate;
HashSet <Proposition> propositions = new HashSet <Proposition>()
{
universalQuantifier
};
// Act
SemanticTableauxElement semanticTableauxElement = new SemanticTableauxElement(propositions);
bool isReplaced = predicate.IsReplaced(boundVariable);
// Assert
isReplaced.Should().BeFalse("Because no replacement variables are available");
semanticTableauxElement.LeftChild.Should().BeNull("Because no replacement variables are available and thus no child was created");
}
public void Constructor_CreateNegatedUniversalQuantifier_DeltaRuleShouldBeAppliedChildShouldBePredicateAndVariableShouldBeIntroduced()
{
// Arrange
char boundVariable = PropositionGenerator.GenerateBoundVariable();
List <char> boundVariables = new List <char>()
{
boundVariable
};
Predicate predicate = new Predicate(PropositionGenerator.GetRandomVariableLetter(), boundVariables);
UniversalQuantifier universalQuantifier = new UniversalQuantifier(boundVariable);
universalQuantifier.LeftSuccessor = predicate;
Negation negatedUniversalQuantifier = new Negation();
negatedUniversalQuantifier.LeftSuccessor = universalQuantifier;
HashSet <Proposition> propositions = new HashSet <Proposition>()
{
negatedUniversalQuantifier
};
// Act
SemanticTableauxElement semanticTableauxElement = new SemanticTableauxElement(propositions);
List <char> replacementVariables = semanticTableauxElement.LeftChild.ReplacementVariables.ToList();
int expectedNumberOfReplacementVariables = 1;
int actualNumberOfReplacementVariables = replacementVariables.Count;
// Assert
actualNumberOfReplacementVariables.Should().Be(expectedNumberOfReplacementVariables, "Because the only bound variable should be replaced based on the rules");
foreach (Proposition proposition in semanticTableauxElement.LeftChild.Propositions)
{
if (proposition is Predicate)
{
predicate = (Predicate)proposition;
bool isReplaced = predicate.IsReplaced(boundVariable);
isReplaced.Should().BeTrue("Because after applying a delta rule, the only bound variable in the predicate should be replaced");
}
}
}
public void Constructor_CreateNegatedExistentialQuantifierWithReplacementVariablePresent_GammaRuleShouldBeAppliedAndNewChildrenCreated()
{
// Arrange
char boundVariable = PropositionGenerator.GenerateBoundVariable();
List <char> boundVariables = new List <char>()
{
boundVariable
};
Predicate predicate = new Predicate(PropositionGenerator.GetRandomVariableLetter(), boundVariables);
ExistentialQuantifier existentialQuantifier = new ExistentialQuantifier(boundVariable);
existentialQuantifier.LeftSuccessor = predicate;
Negation negatedExistentialQuantifier = new Negation();
negatedExistentialQuantifier.LeftSuccessor = existentialQuantifier;
HashSet <Proposition> propositions = new HashSet <Proposition>()
{
negatedExistentialQuantifier
};
// Act
char availableReplacementVariable = 'd';
SemanticTableauxElement semanticTableauxElement = new SemanticTableauxElement(propositions, new HashSet <char>()
{
availableReplacementVariable
});
// Assert
semanticTableauxElement.LeftChild.Should().NotBeNull("Because children should be created now that a replacement variable is present");
foreach (Proposition proposition in semanticTableauxElement.LeftChild.Propositions)
{
if (proposition is Predicate)
{
Predicate pred = (Predicate)proposition;
bool isReplaced = pred.IsReplaced(boundVariable);
isReplaced.Should().BeTrue($"Because the replacement variable {availableReplacementVariable} is available");
}
}
}
