The Assam Sales Tax Act, 1947, had incorporated therein an addition to the charging section (section 3 of the Act) and section 3 (1 A) which was inserted by section 3 of the Assam Sales Tax (Amendment) Act, 1947 (Assam Act IV of 1951) was to the following effect: "Nothing in sub section (1) shall,except in cases covered by the first proviso to sub section (12) of section 2 of this Act be deemed to render any dealer 849 liable to tax on the sale of goods where such sale takes place: (1) outside the State of Assam; (2) in the course of the import of the goods into, or export of the goods out of, the territory of India; or (3) in the course of inter State trade or commerce except in so far as Parliament may by law otherwise provide.