Explain "Static approach" and "Ambulatory approach" with regard to meaning of a term as per the domestic law, not defined in the International Tax…

Static Approach – Under static approach, a term not defined in the treaty to be assigned the meaning as per the domestic law which prevailed on the date of signing the international tax treaty. Ambulatory Approach – Under Ambulatory approach, a term not defined in the treaty to be assigned the meaning as per the domestic law which is prevailing on the date of application of the international tax treaty. All Model Commentaries favour ambulatory approach, however with one caution that such approach cannot be applied when there is a radical amendment in the domestic law thereby changing the sum and substance of the said term.