R. K. GULATI, J. - (1.) The petitioner, a partnership concern, was assessed under the Central Sales Tax Act, 1956, for the assessment year 1983-84 by an order dated 17th June, 1985, a copy of which is annexure-I to the writ petition. Subsequent to the making of the said order, the petitioner was served with a notice for reassessment under section 21 of the U. P. Sales Tax Act, 1948 (for short "the Act" ). By means of this writ petition, the petitioner has challenged the validity of the reassessment proceedings. The petitioner seeks issuance of a writ of certiorari for quashing of the notice under section 21 and also a writ of prohibition to the Sales Tax Officer, Circle 20, Kanpur, the sole respondent, directing him to desist from taking any further proceedings in pursuance of the said notice under section 21. At the admission stage of the writ petition, parties have exchanged their affidavits. The petition is ripe for hearing. With the consent of the parties we proceed to dispose of this writ petition finally. Shri M. Katju, learned counsel appearing for the petitioner, urged that the impugned notice for reassessment is without jurisdiction, inasmuch as, there was no turnover which could be said to have escaped assessment to tax in the original assessment. Further, the respondent-assessing officer had no material in his possession on which he could have had reason to believe that any part of the petitioner's turnover for the year in question has escaped assessment to tax. The main thrust of the argument was that the impugned action has been taken as a result of change of opinion, which is not permissible within the purview of section 21 of the Act. A scrutiny of sub-section (1) of section 21 of the Act, which confers power on the assessing authority to reopen assessment in order to assess the correct amount of tax payable, would show that it comes into operation when the assessing authority has "reason to believe" that the whole or any part of the turnover of a dealer, for any assessment year or part thereof, has escaped assessment to tax, or has been under-assessed or has been assessed to tax at a rate lower than that at which it is assessable under the Act, or any deduction or exemption has been wrongly allowed in respect, thereof. Thus, a notice under section 21 must precede a condition precedent, namely, the formation of opinion on the part of the assessing authority that there is "reason to believe" that the case in which the action is contemplated falls within the ambit of at least one of the several contingencies mentioned nnder that section. The expression "reason to believe" is to be found in various statutes. We may take note of section 34 of the Indian Income-tax Act, 1922, which like section 21 of the Act, inter atia, provides that the Income-tax Officer must have "reason to believe" that income, profit or gains chargeable to income-tax has been under-assessed, and then alone he can take action under section 34. As to what constitutes "reason to believe" and to what extent the question may be examined by the court was considered by the Snpreme Court in S. Narayanappa v. Commissioner of Income-tax, Bangalore [1967] 63 ITR 219. While construing that expression under section 34 aforesaid it was observed : " The expression 'reason to believe' in section 34 does not mean a purely subjective satisfaction on the part of the Income-tax Officer. The belief must be held in good faith; it cannot be merely a pretence. It is open to the court to examine whether the reasons for the belief have a rational connection or a relevant bearing to the formation of the belief and are not extraneous or irrelevant to the purpose of the section. To this limited extent, the action of the Income-tax Officer in starting proceedings under section 34 of the Act is open to challenge in a court of law. " Now, the belief of the assessing authority cannot be purely subjective and it must be held upon relevant material, howsoever meagre. The reasons for the belief must have a rational connection or live-link between the material coming in possession of the assessing authority and the escapement of the turnover of the assessee from assessment in a particular year, or a part of the year. In short, if there are in fact, some reasonable grounds for the assessing officer to believe and form an opinion objectively that turnover has escaped assessment, the assessing authority would be well within its jurisdiction to take action under section 21 of the Act. For the Revenue it was contended that the notice under section 21 of the Act was issued on the basis of the material which warranted a reasonable belief that the turnover of the petitioner had been under-assessed. The challenge to the jurisdiction of the respondent to reopen the assessment has been refuted in clear terms in the counter-affidavit filed by the assessing officer. This stand of the respondent is backed by averments contained in paragraphs 6 to 9 of the counter-affidavit. In brief, three grounds have been stated. These are : (i) Purchases shown in the trading account by the petitioner were Rs. 6,38,502. 77 whereas purchases as per purchase lists, which were made available by the petitioner itself are Rs. 9,89,492. 60. It is claimed by the respondent that this fact was not considered by the assessing officer during the original assessment proceedings. (ii) Closing stock of Rs. 50,33,245. 20 has not been taxed and the firm is said to be closed. (iii) An information was received from a dealer, namely, M/s. Sanjay Box Industries, Kanpur, on 23rd March, 1988, i. e. , after the passing of the original assessment order, that purchases amounting to Rs. 68,042 were made by the petitioner from that dealer in 1983-84, which were against form 3-D, while the petitioner had disclosed purchases from that dealer as Rs. 67,982 which was less than that in the information received. It is also asserted that on the scrutiny of the above information, certain other discrepancies were also noticed. On the basis of the material mentioned in the counter-affidavit, the learned counsel for the Revenue urged that the notice issued to the petitioner under section 21 was valid and the material in possession of the assessing officer was such which warranted formation of opinion objectively that part of the petitioner's turnover which was chargeable to tax during the year in question had escaped assessment. In the affidavit filed in opposition to the counter-affidavit, the petitioner has denied the first ground in the following terms : "the Sales Tax Officer had added up the list of returned goods and passing material which comes under different heads in the books of account. " With regard to the closing stock it is asserted that the firm was never closed on 31st March, 1984 and returns have regularly been filed every month in the subsequent years. Referring to the third ground, i. e. , the information received from M/s. Sanjay Box Industries, it is impliedly admitted that the difference does exist, but it is claimed that as the difference was of Rs. 60 only, that could not be a valid ground for reopening the entire assessment under section 21 of the Act. After hearing the learned counsel for the parties and having given our careful consideration to the case set up by the contesting parties, we are of the opinion that this writ petition must fail. From a perusal of the original assessment order, annexure-I to the writ petition, it is evident that there is no consideration in the assessment order about the difference regarding purchases as per the trading account and that disclosed as per purchase lists. The explanation given in the rejoinder affidavit that such difference, which is to the extent of one-third of purchases disclosed in the purchase list, was on account of return of certain goods, is of no assistance to the petitioner in these proceedings. No attempt has been made in the affidavits filed by the petitioner to explain the huge difference by facts and figures. A mere denial in a vague manner can hardly be of any help to dislodge the case of the Revenue for taking the impugned action. Sri M. Katju contended that in any case, on the department's own showing the purchase lists were made available by the petitioner itself and if the assessing authority had failed to apply its mind in the original assessment proceedings, for no fault of the petitioner, the action for reassessment cannot be sustained. It was argued that no fresh information had come in possession of the assessing officer after the original assessment, as a result of which the impugned action for reassessment was taken. Proceeding along, it was argued that on the basis of the case set up in the counter-affidavit at best it may be a case of change of opinion, but no action for reassessment on that account can be sustained under section 21 of the Act. There is no merit in the submissions advanced on behalf of the petitioner. In the first instance there is nothing on record to suggest that the purchase lists were made available to the assessing authority, when the original assessment was framed. The counter-affidavit clearly indicates that on receipt of the information from M/s. Sanjay Box Industries, which was received after the original assessment, some inquiries were made by the assessing authority when the discrepancies were noticed. It does not rule out the possibility that lists were obtained by the assessing officer subsequent to the original assessment. However, this question need not detain us. Assuming, purchase lists were on record when the original assessment took place, even then, the petitioner cannot succeed. Section 21 of the Act is based upon the theory that the taxes must be paid by the assessee in correct sum and likewise it must be collected by the statutory machinery. The escapement from assessment whether it results on account of concealment practised or fraud played by the assessee or as a result of negligence or ignorance of the assessing authority, in our opinion, is of no consequence, provided the action to reopen the assessment is otherwise justified and the assessing officer is not acting arbitrarily or in a capricious manner. The escapement of assessment contemplated under that section may be due to various reasons. The term "turnover has escaped assessment to tax" which includes under-assessment, may as well be the result of lack of care on the part of the assessing officer or by reason of inadvertence on his part. Section 21 does not prohibit obtaining of information from the investigation of material on the record of the original assessment. The scope of that section is not circumscribed by a rider like the one that exists in section 147 (a) of the Income-tax Act, 1961, namely, the Income-tax Officer has reason to believe that by reason of the omission or failure on the part of the assessee to disclose fully and truly all material facts necessary for the assessment for that year, income chargeable to tax has escaped assessment for that year. The escapement envisaged by section 21 of the Act for the purposes of reassessment need not necessarily spring from a source extraneous to the original record. However, a second thought or a mere change of opinion, by the assessing authority on the same set of facts and the material on the record would not clothe the assessing authority with a valid jurisdiction. The section with which we are concerned is in close proximity and is in pari materia with section 147 (b) of the Income-tax Act, where the action for reassessment is contemplated notwithstanding that there was no omission or failure on the part of the assessee as aforesaid. The mere filing of a document either along with the return or otherwise without anything more does not ipso facto take away the jurisdiction of the assessing authority to take action under section 21 of the Act. In Commissioner of Income-tax, Gujarat v. A. Raman and Co. [1968] 67 ITR 11, the Supreme Court while dealing with a matter under section 147 (b) of the Income-tax Act, 1961 pointed as under : " Jurisdiction of the Income-tax Officer to reassess income arises if he has in consequence of information in his possession reason to believe that income chargeable to tax has escaped assessment. That information must, it is true, have come into the possession of the Income-tax Officer after the previous assessment but even if the information be such that it could have been obtained during the previous assessment from an investigation of the material on record, or the facts disclosed thereby, or from other enquiry or research into facts or law, but was not in fact obtained, the jurisdiction of the Income-tax Officer is not affected. " Although the above decision was given with reference to section 147 (b) of the Income-tax Act, but so far the issue with which we are concerned, the said section, as already noted, is in pari materia with section 21 of the Act. In finding out the meaning of the expression "escaped assessment" or "has been under-assessed" envisaged by section 21 of the Act, we see no reason why the said expressions should bear a more limited meaning than that it bears under section 147 (b) of the Income-tax Act. The object of the two sections under the two statutes is to gather the revenue which has improperly escaped and both the Acts deals with taxing statutes. For the petitioner reliance was placed on a decision of this Court in Commissioner of Sales Tax, U. P. v. Pradeep Kumar Sanjeev Kumar [1987] 67 STC 146; 1987 UPTC 511. That case is clearly distinguishable and in fact, does not deal with the point with which we are concerned in this case. In that case, there was no challenge to the initiation of proceedings under section 21 of the Act. The reassessment was not sustained on the findings that the assessing officer had failed to make certain enquiries before drawing an adverse inference that, the turnover in question was liable to tax under the Act, for which action under section 21 was taken. We were also referred to another decision of this Court in Commissioner of Sales Tax, U. P. , Lucknow v. Panna Lal Gupta 1988 UPTC 441. That case is again distinguishable. All that had been held there was that reassessment of the same turnover already considered in the original assessment without any fresh material is not justified under section 21 of the Act. We are not impressed by the argument that the instant case is a case of change of opinion. The change of opinion necessarily postulates that the assessing authority had an occasion to consider the material earlier, and on the same set of facts another opinion was sought to be formed. The question of change of opinion cannot arise where there has been no previous proceeding of assessment in respect of a turnover in dispute. As pointed out by the Calcutta High Court in Income-tax Officer v. Mahadeo Lal Tulsyan [1978] 111 ITR 25, a change of opinion by the assessing officer contemplates formation of two different opinions or to make two different inferences at two stages on the same set of primary facts. The distinction between an inadvertent mistake or omission and change of opinion was pointed out by one of us after reviewing a large number of decided cases, both by this Court and by the Supreme Court, in Commissioner of Sales Tax, U. P. v. Madhu Chemical Works, Bareilly [1988] 71 STC 421 (All.); 1988 UPTC 230. It was held that in a case where a particular point has been considered on merits, and a view is taken, it would not be a case of inadvertent mistake or omission, if it is found that the view taken earlier was wrong. It would be a case of change of opinion, but if it is not so, then it would be a case of non-application of mind and an action would be justified under section 21 of the Act. As stated earlier, there is nothing on the record of this writ petition to show that the assessing authority was aware of the difference in the quantum of purchases as per the purchase lists and those disclosed in the trading account, much less the matter was considered at the time of the original assessment. Accordingly, we reject the submission that the impugned action is a result of change of opinion. After the issuance of the impugned notice under section 21, it appears that the petitioner had appeared before the respondent-assessing officer at least on three different occasions between 10th August, 1988 to 3rd September, 1988. However, when a show cause notice was issued requiring the assessee to explain the material on which notice under section 21 was based, the petitioner instead of filing an appropriate reply has rushed to this Court seeking the quashing of the impugned notice and for a writ of prohibition. In the proceedings under article 226 of the Constitution, the onus is on the petitioner to establish that there was complete absence of jurisdiction of the assessing officer to initiate proceedings under section 21 and that such lack of jurisdiction is patent on the face of the record without requiring any investigation into facts. We are not satisfied that in the instant case, the impugned notice is based on purely subjective opinion of the assessing authority. We are fully satisfied that there was material before the respondent-assessing authority, which would furnish him grounds for entertaining a "reasonable belief" contemplated under section 21 of the Act. In these proceedings, we cannot go into the question of sufficiency of evidence which falls within the jurisdiction of the assessing authority to decide. The remedy by way of a writ of prohibition under article 226 of the Constitution cannot be claimed on these matters. It is settled, that no writ of prohibition can be issued unless it is shown that the authority is acting without jurisdiction, which the petitioner has failed to establish in the instant case. In view of our above discussion, it is not necessary for us to deal with the other contentions of the learned counsel for the petitioner, namely, on a meagre amount of Rs. 60 no action under section 21 of the Act could have been taken by the Sales Tax Officer, the argument being that the law does not take notice of trivialities. This petition is without any substance and is accordingly dismissed. Writ petition dismissed. .;