title: Creating an if-statement in mathematical modelling
body: <p>Im trying to make a mathematical model for flexible job shop scheduling. In this model, operations can be divided into certain sub-groups, and relations between operations in the subgroup, and those outside of it can be defined. If an operation belongs in subgroup <em>y</em> the operations y value would be 1, and otherwise it will be set to 0. Whenever I create a relation between two operations i can the use a sufficiently large number L so that</p>
  
  <blockquote>
    <p>T1+((1-y1)*L)&lt;= T2+((1-y2)*L)</p>
  </blockquote>
  
  <p>This ensures that the T value of operation 1 is smaller than that of operation 2 if operation 1 belongs in subgroup y, and operation 2 doesn't.</p>
  
  <p>While this method works as a improvised if-statement, it seems incredibly clunky, does anyone know of a better way to achieve the same effect?</p>