public REXClassExpressionImpl getMax(int n, REXObjectPropertyExpressionImpl role){
		
		if(maxs.containsKey(n) && maxs.get(n).containsKey(role))
			return maxs.get(n).get(role);
		if(mins.containsKey(n+1) && mins.get(n+1).containsKey(role) && mins.get(n+1).get(role).complement != null)
			return mins.get(n+1).get(role).complement;
		return null;
	}