title: Genetic alghorithm / Linear-rank selector , the problem with meaning of the variables
body: <p>I have the equation of probability of choicing an induvidual in Linear-rank selector.</p>
  <pre><code>P(i) = (1/N) * (n− + (n+ − n− )* ( i−1 / N−1) )
  </code></pre>
  <p>tell me please , what is  <strong>n-</strong>  and  <strong>n+</strong>  ?</p>