code: protected void sequence_Negation(ISerializationContext context, Negation semanticObject) {
  		if (errorAcceptor != null) {
  			if (transientValues.isValueTransient(semanticObject, XtextPackage.Literals.NEGATION__VALUE) == ValueTransient.YES)
  				errorAcceptor.accept(diagnosticProvider.createFeatureValueMissing(semanticObject, XtextPackage.Literals.NEGATION__VALUE));
  		}
  		SequenceFeeder feeder = createSequencerFeeder(context, semanticObject);
  		feeder.accept(grammarAccess.getNegationAccess().getValueNegationParserRuleCall_1_2_0(), semanticObject.getValue());
  		feeder.finish();
  	}
docs: Contexts:
  Disjunction returns Negation
  Disjunction.Disjunction_1_0 returns Negation
  Conjunction returns Negation
  Conjunction.Conjunction_1_0 returns Negation
  Negation returns Negation
  Atom returns Negation
  ParenthesizedCondition returns Negation
  
  Constraint:
  value=Negation