code: public Binding evaluate(Map symbolTable)
  	throws RslEvaluationException {
  	String strValue = _value.evaluate(symbolTable);
  	return new Binding(getName(), new Value(strValue));
      }
docs: Evaluates the variable definition with the specified
  symbol table.
  
  @param symbolTable the symbol table to evaluate
  the value against.
  @return an evaluated string.
  @exception RslEvaluationException If an error occured during
  rsl evaluation.