“ 14 . In view of the afore-stated legal position, it clearly emerges that though the doctrine “equal pay for equal work” is not an abstract doctrine and is capable of being enforced in a Court of Law, the equal pay must be for equal work of equal value. The equation of posts and determination of pay scales is the primary function of the Executive and not of the Judiciary. The Courts therefore should not enter upon the task of job evaluation which is generally left to the expert bodies like the Pay Commissions which undertake rigorous exercise for job evaluation after taking into consideration several factors like the nature of work, the duties, accountability and responsibilities attached to the posts, the extent of powers conferred on the persons holding a particular post, the promotional avenues, the Statutory rules governing the conditions of service, the horizontal and vertical relativities with similar jobs etc. It may be true that the nature of work involved in two posts may sometimes appear to be more or less similar, however, if the classification of posts and determination of pay scale have reasonable nexus with the objective or purpose sought to be achieved, namely, the efficiency in the administration, the Pay Commissions would be justified in recommending and the State would be justified in prescribing different pay scales for the seemingly similar posts. A higher pay scale to avoid stagnation or resultant frustration for lack of promotional avenues or frustration due to longer duration of promotional avenues is also an acceptable reason for pay differentiation. It is also a well-accepted position