code: function(eqn) { 
          //If it's an equation then call its toLHS function instead
          if(eqn instanceof Equation)
              return eqn.toLHS();
          var es = eqn.split('=');
          if(es[1] === undefined) es[1] = '0';
          var e1 = _.parse(es[0]), e2 = _.parse(es[1]);
          return removeDenom(e1, e2);
      }
docs: A utility function to parse an expression to left hand side when working with strings