public override string GetProof() { var sb = new StringBuilder(); IList <Literal> nLits = implication.GetNegativeLiterals(); for (int i = 0; i < implication.GetNumberNegativeLiterals(); i++) { sb.Append(nLits[i].AtomicSentence); if (i != (implication.GetNumberNegativeLiterals() - 1)) { sb.Append(" AND "); } } sb.Append(" => "); sb.Append(implication.GetPositiveLiterals()[0]); return(sb.ToString()); }