/// <summary>
 /// This property signs if an expression is ready to be evaluated,
 /// namely, all subexpression values are known
 /// </summary>
 /// <param name="evalContext">Evaluation context</param>
 /// <returns>True, if the expression is ready; otherwise, false</returns>
 public override bool ReadyToEvaluate(IEvaluationContext evalContext)
 => Condition.ReadyToEvaluate(evalContext) &&
 TrueExpression.ReadyToEvaluate(evalContext) &&
 FalseExpression.ReadyToEvaluate(evalContext);