private static PassiveExpression PreAlph(PassiveExpression expression) { Pattern pattern2 = new Pattern(new SymbolVariable("s.1"), new SymbolVariable("s.1")); if (RefalBase.Match(expression, pattern2)) { return(PassiveExpression.Build(true)); } ; Pattern pattern3 = new Pattern(new SymbolVariable("s.1"), new SymbolVariable("s.2")); if (RefalBase.Match(expression, pattern3)) { PassiveExpression expression4 = PassiveExpression.Build(Alphabet(PassiveExpression.Build())); Pattern pattern4 = new Pattern(new ExpressionVariable("e.A"), new SymbolVariable("s.1"), new ExpressionVariable("e.B"), new SymbolVariable("s.2"), new ExpressionVariable("e.C")); pattern4.BindVariables(pattern3); if (RefalBase.Match(expression4, pattern4)) { return(PassiveExpression.Build(true)); } ; } ; Pattern pattern5 = new Pattern(new ExpressionVariable("e.Z")); if (RefalBase.Match(expression, pattern5)) { return(PassiveExpression.Build(false)); } ; throw new RecognitionImpossibleException("Recognition impossible"); }