private static bool BoxStartsHere(ProofLineRef reference, IEnumerable<ProofBox> boxes)
{
return boxes.Any(pb => pb.Start == reference);
}
public static Rule Parse(string text)
{
text = text.Trim();
if (text.StartsWith("premise"))
return new PremiseRule();
if (text.StartsWith("assumption"))
return new AssumptionRule();
if (text.StartsWith("copy"))
{
return new CopyRule(new ProofLineRef(text.Substring(4).Trim()));
}
if (text.StartsWith("∧i"))
{
string[] parts = text.Substring(2).Split(',').Select(s => s.Trim()).ToArray();
return new ConjunctionIntroductionRule(new ProofLineRef(parts[0]), new ProofLineRef(parts[1]));
}
if (text.StartsWith("∧e"))
{
int index = text[2] == '_' ? 3 : 2;
int variant = text[index] == '1' ? 1 : 2;
ProofLineRef to = new ProofLineRef(text.Substring(index + 1).Trim());
return new ConjunctionEliminationRule(to, variant);
}
if (text.StartsWith("∨i"))
{
int index = text[2] == '_' ? 3 : 2;
int variant = text[index] == '1' ? 1 : 2;
ProofLineRef to = new ProofLineRef(text.Substring(index + 1).Trim());
return new DisjunctionIntroductionRule(to, variant);
}
if (text.StartsWith("∨e"))
{
string[] parts = text.Substring(2).Split(',').Select(s => s.Trim()).ToArray();
return new DisjunctionEliminationRule(new ProofLineRef(parts[0]), ProofBox.Parse(parts[1]), ProofBox.Parse(parts[2]));
}
if (text.StartsWith("¬¬i"))
{
ProofLineRef to = new ProofLineRef(text.Substring(3).Trim());
return new NegNegIntroductionRule(to);
}
if (text.StartsWith("¬¬e"))
{
ProofLineRef to = new ProofLineRef(text.Substring(3).Trim());
return new NegNegEliminationRule(to);
}
if (text.StartsWith("→i"))
{
ProofBox box = ProofBox.Parse(text.Substring(2).Trim());
return new ImpliesIntroductionRule(box);
}
if (text.StartsWith("→e"))
{
string[] parts = text.Substring(2).Split(',').Select(s => s.Trim()).ToArray();
return new ImpliesEliminationRule(new ProofLineRef(parts[0]), new ProofLineRef(parts[1]));
}
if (text.StartsWith("¬i"))
{
ProofBox box = ProofBox.Parse(text.Substring(2).Trim());
return new NegIntroductionRule(box);
}
if (text.StartsWith("¬e"))
{
string[] parts = text.Substring(2).Split(',').Select(s => s.Trim()).ToArray();
ProofLineRef line = new ProofLineRef(parts[0]);
ProofLineRef negLine = new ProofLineRef(parts[1]);
return new NegEliminationRule(line, negLine);
}
if (text.StartsWith("⊥e"))
{
ProofLineRef bot = new ProofLineRef(text.Substring(2).Trim());
return new BotEliminationRule(bot);
}
if (text.StartsWith("MT"))
{
string[] parts = text.Substring(2).Split(',').Select(s => s.Trim()).ToArray();
ProofLineRef impl = new ProofLineRef(parts[0]);
ProofLineRef negConcl = new ProofLineRef(parts[1]);
return new ModusTollensRule(impl, negConcl);
}
if (text.StartsWith("PBC"))
{
ProofBox box = ProofBox.Parse(text.Substring(3).Trim());
return new ProofByContradictionRule(box);
}
if (text.StartsWith("LEM"))
{
return new LawOfExcludedMiddleRule();
}
return null;
}
public bool Equals(ProofLineRef other)
{
return string.Equals(To, other.To, StringComparison.Ordinal);
}
