In the pseudo-code it is the function: relation-classifier (production, sentence, range1, range2, sub-card-pyramid1, subcard-pyramid2), where range1 and range2 are the ranges of the word indices of the two entities and sub-card-pyramid1 and sub-card-pyramid2 are the sub-card-pyramids rooted at its two children.
along with the two entities and the words in the sentence, information from these subcard-pyramids is also used in deciding the relation at a node.