Question: what is the formula to calculate the lift that x implies y given that?
Answer: lift: The lift of a rule is defined as lift(X implies Y) = supp(X ∪ Y)/((supp(Y) x supp(X)) or the ratio of the observed support to that expected if X and Y were independent. Lift can also be defined as lift(X implies Y) =conf(X implies Y)/supp(Y).