It specifies the extent of compatibility for a single predicate between different typed entailment graphs, with 1 being completely compatible and 0 being irrelevant.
β p, (t 1 , t 2 ), (t 1 , t 2 ) determines how much we expect the outgoing edges of p(:t 1 , :t 2 ) and p(:t 1 , :t 2 ) to be similar.