title: How is an if statement possible with decision variables in CPLEX
body: <p>How can I formulate my model that it undertakes a maintenance at 450 and a cleaning at 150?    </p>
  
  <pre><code>forall(w in W, t in T, s in S, p in P, m in M)  
     (450&lt;=hub[m][w][t][s])&lt;=(b_maint[w][m][t][s]==1);
  
  forall(w in W, t in T, s in S, p in P, m in M)  
     (hub[m][w][t][s]&gt;=150)&lt;=(b_clean[w][m][t][s]==1);
  </code></pre>
  
  <p>I also want that after my maintenance the hub is set back to 0
  (hub is my production quantity) Is this formulation right?.</p>
  
  <pre><code>forall(w in W, t in T, s in S, p in P, m in M)  
     (b_maint[w][m][t][s]==1)==(hub[m][w][t][s]==0);
  </code></pre>
  
  <p>And can i also model bounds like this:</p>
  
  <pre><code>forall(w in W, t in T, s in S)  
     (135&lt;=sum(p in P, m in M)r_x[m][w][p][t][s] &amp;&amp; sum(p in P, m in M)r_x[m][w][p][t][s]&lt;=185)==(b_clean[w][t][s]==1);
  </code></pre>
  
  <p>I tried it also already like this:                      </p>
  
  <pre><code>(135&lt;=sum(p in P, m in M)r_x[m][w][p][t][s] &lt;=185)==(b_clean[w][t][s]==1);
  </code></pre>
  
  <p>but that doesn't work either...</p>