public void CreateDisjunctiveNormalForm_NegatedProposition_ExpectedOriginalNegatedPropositionReturned()
{
// Arrange
Proposition originalProposition = PropositionGenerator.CreateUnaryConnectiveWithRandomSymbol(Negation.SYMBOL);
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 negated proposition literal is the negated literal itself");
simplifiedDnf.Should().BeEquivalentTo(originalProposition, "Because a negated literal can not be simplified any further and should result in the negated literal itself.");
}
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 CreateDisjunctiveNormalForm_ExpressionGiven_ExpectedPropositionLiteralsAtTheLeavesAndNoDisjunctionDeeperThanConjunction(char expressionSymbol)
{
// For the binary connectives, we should check all (both) possible branches if they contain
// no disjunction below a conjunction
// Arrange
BinaryConnective root = PropositionGenerator.CreateBinaryConnectiveWithRandomSymbols(expressionSymbol);
TruthTable tt = new TruthTable(root);
TruthTable simplifiedTt = tt.Simplify();
// Act
Proposition dnf = tt.CreateDisjunctiveNormalForm();
Proposition simplifiedDnf = simplifiedTt.CreateDisjunctiveNormalForm();
// Assert
Assert.True(IsInDnf(dnf), "Because this expression should be in DNF");
Assert.True(IsInDnf(simplifiedDnf), "Because the simplified expression should also be in DNF");
}