In Section 12.4.2 we have illustrated a few ways to represent logical constraints. Suppose that activity i must be started if and only if both activities j and k are started. By introducing customary binary variables, it is tempting to write a constraint like Xi = XjXk\ unfortunately, this is a bad nonlinear constraint. How can we express this logical constraint linearly?

Generalize the idea and find a way to linearize the product ΠΓ= x* °^ n binary variables.