Finally, the left attribute is considered.
since neither R1 or R7 are on the left side of anything sufficiently close for the purpose of reference (and therefore do not have a left property defined in the knowledge base), (left-R6) is also added to L, and both distractors are removed from C. the context C is now empty, and the algorithm terminates by returning the expression L = {(type, monster), (left, R6)}, in which case R6 itself could be described recursively as {(type, cactus)}.