public IConceptSet lookupB(int A, int r) {
        if (A >= CONCEPTS || r >= ROLES) {
            return IConceptSet.EMPTY_SET;
        }
        final int index = indexOf(A, r);
        if (null == data[index]) {
            if (null != base && index < base.length && null != base[index]) {
                data[index] = new SparseConceptSet();
                data[index].addAll(base[index]);
                return new ReadonlyConceptSet(data[index]);
            } else {
                return IConceptSet.EMPTY_SET;
            }
        } else {
            return new ReadonlyConceptSet(data[index]);
        }
    }
public IConceptSet lookupB ( int A , int r ) { if ( A >= CONCEPTS || r >= ROLES ) { return IConceptSet . EMPTY_SET ; } final int index = indexOf ( A , r ) ; if ( null == data [ index ] ) { if ( null != base && index < base . length && null != base [ index ] ) { data [ index ] = new SparseConceptSet ( ) ; data [ index ] . addAll ( base [ index ] ) ; return new ReadonlyConceptSet ( data [ index ] ) ; } else { return IConceptSet . EMPTY_SET ; } } else { return new ReadonlyConceptSet ( data [ index ] ) ; } }
@param A
@param r
@return Set of concepts B such that A [ r.B