“40. In the case of the present petitioners, therefore, the appointment preceded a prescribed procedure contemplated under the statutory rules and after they were appointed on a substantive existing vacant post, their appointment was not as a stop gap arrangement on a consolidated salary, but it was in the pay scale prescribed under the statutory rules. Not only were they appointed on the pay prescribed in the statutory rules, but the benefit of increment in accordance to the prescribed pay scale, revision of pay scale from time to time and all other benefits accruing to a regularly appointed incumbent under Rule 12 was extended to the petitioners. Benefit of leave of all kinds under the leave rules, additional increment on acquiring extra qualification, benefit of provident fund and even posting on higher post on officiating capacity was extended to the petitioners. It is, therefore, a case where the petitioners for all practical purposes were treated as regularly appointed incumbents to the service of the department and treating them to be so appointed all service benefits as per the Rules were extended. It is not a case where the petitioners were inducted into the department by any irregular method or by adopting back door entry method or by a pick and choose discriminatory and arbitrary system of appointment. On the contrary, they are appointed in accordance to a mode prescribed under the statutory rules on existing substantive vacant post and all benefit of regular