elk-reasoner/src/main/java/org/semanticweb/elk/reasoner/saturation/conclusions/classes/ClassConclusionOccurrenceCheckingVisitor.java
@Override
	protected Boolean defaultVisit(ClassConclusion conclusion) {
		ClassConclusionSet conclusions = conclusionsRef_.get();		
		boolean result = conclusions == null
				? false
				: conclusions.containsConclusion(conclusion);
		if (LOGGER_.isTraceEnabled()) {
			LOGGER_.trace("{}: check occurrence of {}: {}", conclusions,
					conclusion, result ? "success" : "failure");
		}
		return result;
	}
@Override
	protected Boolean defaultVisit(ClassConclusion conclusion) {
		ClassConclusionSet conclusions = conclusionsRef_.get();		
		boolean result = conclusions == null
				? false
				: conclusions.containsConclusion(conclusion);
		if (LOGGER_.isTraceEnabled()) {
			LOGGER_.trace("{}: check occurrence of {}: {}", conclusions,
					conclusion, result ? "success" : "failure");
		}
		return result;
	}
logging is switched off