Towards Reverse Engineering of PDF Documents

summary:We present a progress report on our ongoing project of reverse engineering scientific PDF documents. The aim is to obtain mathematical markup that can be used as source for regenerating a document that resembles the original as closely as possible. This source can then be a basis for further document processing. Our current tool uses specialised PDF extraction together with image analysis to produce near perfect input for parsing mathematical formula. Applying a linear grammar and specific drivers for each output format to this input, we can produce an accurate reproduction of formulae when presented with their coordinates. In this paper we will show how this information can be exploited to discover the locations of both inline and display formulae, and also to perform rudimentary layout analysis of the whole document, identifying structures such as headings and paragraphs

A Term Rewriting System for Kuratowski\u27s Closure-Complement Problem

We present a term rewriting system to solve a class of open problems that are generalisations of Kuratowski\u27s closure-complement theorem. The problems are concerned with finding the number of distinct sets that can be obtained by applying combinations of axiomatically defined set operators. While the original problem considers only closure and complement of a topological space as operators, it can be generalised by adding operators and varying axiomatisation. We model these axioms as rewrite rules and construct a rewriting system that allows us to close some so far open variants of Kuratowski\u27s problem by analysing several million inference steps on a typical personal computer

Cold Kaons from Hot Fireballs

The E814-collaboration has found a component of very low $m_t$ $K^+$ mesons with a slope parameter of $T \sim 15 \, \rm MeV$. We will present a scenario which explains the observed slope parameter and which allows us to predict the expected slope parameter for kaons produced in heavier systems such as Au+Au. Implications for the restoration of chiral symmetry in relativistic heavy ion collisions are discussed.(figures are being sent on request)Comment: 9 pages, 4 figures, SUNY-NTG-94-2