A.P.Chowdhri, J.

1. In these writ petitions (Nos. 5691, 7317, 9565, 9564, 10277, 13602 and 13802 of 1989, 5393 and 9022 of 1990 and 337, 1331, 1501, 3764, 3984, 4696 to 4698, 9455 of 1992 and 16812 and 16813 of 1991) the main surviving challenge is to certain amendments made in Section 2 of the Haryana General Sales Tax Act, 1973 (for short, the HGST Act) by the Haryana General Sales Tax (Amendment) Act (Haryana Act No. 1 of 1989) (for short, the Amending Act of 1989). These petitions came up for hearing before a Division Bench of this Court. The learned Judges observed that the question relating to the constitutional validity of the Amending Act of 1989 was one of great public importance and accordingly referred the same to the Full Bench by order dated June 3, 1992. This is how these petitions are before us.

2. For giving the factual background, it would be convenient to group these petitions in different sets.

3-4 In the first set of CWP Nos. 5691, 9565, 9564, 10277, 13602 and 13812 of 1989, 5393 and 9022 of 1990 and 1331, 1501 of 1992 and 16812 & 16816 of 1991, the facts in CWP No. .10277 of 1989 are fairly representative and may be briefly stated as follow ;--

The peti