(1.) The common question arising in these three writ petitions is, whether the petitioners, who are holding mining leases in respect of a major mineral (limestone), can be said to be the purchasers of limestone mined by them. The petitioners are manufacturers of cement, and they use the limestone mined by them for their own manufacturing purposes. The question arises under the Andhra Pradesh General Sales Tax Act, 1957 (hereinafter referred to as "the Act"). Section 6-A of the Act provides, inter alia :
(2.) Section 5 is the charging section, while section 6 deals with tax in respect of declared goods.
(3.) It is necessary to state a few facts for a proper appreciation of the question at issue. It would be sufficient if we set out the facts in W.P. No. 6307 of 1980, the first among the three writ petitions.