Let's assume we have event $i=1,2,\cdots,k$, denoted as $\text{event}_i$. We know for a fact that $\text{event}_i$ is smaller then $\text{event}_{i+1}$ i.e., $\text{event}_i \leq \text{event}_{i+1}$. Now we have given some events $a,b,c,d \leq k$. How do I formulate the constraint that: if $\text{event}_a \leq \text{event}_b$ then $\text{event}_c \leq \text{event}_d$?
My try was:
\begin{align}\text{event}_a + Mz &> \text{event}_b\\\text{event}_c + M(1-z) &\leq \text{event}_d\end{align} where $z \in\{0,1\}$, $M$ large.