title: cplex: define custom mathematical function
body: <p>I want to define a custom function <em>f</em> in the implementation of my optimisation model in cplex, but some mathematical functions are not available. I want to use my customised function <em>f</em> to make a relation between two of my model variables decisions. Here in how is defined <em>f(x)</em> (it is the CDF of normal distribution):</p>
  <p>Thank you for any detail!</p>
  <p><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/187f33664b79492eedf4406c66d67f9fe5f524ea" alt="cutom function" /></p>