Enigma 1225: Prolog-assisted solution of a puzzle using discrete mathematics

A constraint-based approach to Enigma 1225

This paper presents a constraint programming approach to the Enigma 1225, a mathematical puzzle published in the New Scientist magazine in February 2003. An approach based on Prolog was published recently. In this paper we give a constraint programming perspective on the problem, highlighting the differences between the two methodologies. We show how problem-specific knowledge can be easily inc...

Discrete mathematics using a computer

The Mathematics of Set Predicates in Prolog

We provide a logical speciication of set predicates ndall and bagof of Prolog. The speciication is given in proof theoretic terms, and pertains to any SLD{resolution based language. The order dependent aspects, relevant for languages embodying a sequential proof search strategy (possibly with side eeects), can be added in an orthogonal way. The speciication also allows us to prove that bagof ca...

chemical recycling of polycarbonate waste using conventional heating and microwave assisted method

پلی کربنات یکی از پلاستیکهای مهمی است که به صورت گسترده در تولید لوحهای فشرده، قطعات رایانه، مواد ساختمانی و غیره مورد استفاده قرار می گیرد. این پلیمر بصورت عمده از تراکم مونومر بیس فنولa (bpa) و کربنیل کلرید یا دی متیل کربنات ها بدست می آید. در سالهای اخیر بازیافت شیمیایی پلی کربنات بیشتر مورد توجه بوده است. بازیافت شیمیایی پلی کربنات برای بدست آوردن مواد اولیه آن با روشهای متفاوتی مانند تجزی...

Solution of Orthopositronium lifetime Puzzle

The intrinsic decay rate of orthopositronium formed in SiO2 powder is measured using the direct 2γ correction method such that the time dependence of the pick-off annihilation rate is precisely determined. The decay rate of orthopositronium is found to be 7.0396 ± 0.0012(stat.) ± 0.0011(sys.)μs, which is consistent with our previous measurements with about twice the accuracy. Results agree well...