title: Symbolic declaration of variables in Matlab
body: <p>I would like to write my variables as operations between other variables.</p>
  
  <p>For instance if I put <code>a = c + b</code>  then value that a keeps inside is the numeric result of the operation of a sum between c and b.</p>
  
  <p>If c = 4 and b = 2 then, the value that a keeps is 6.</p>
  
  <p>But I would like that a keeps the symbolic expression instead of the numeric value.
  and every time I write a in the command windows, matlab cacht the numeric value of c and the numeric value of b of the worspace variable and  a sum them.</p>
  
  <p>Normally if you write a, matlab displays the numeric value that is in this variable.
  Does anyone know how to do this?</p>