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7 <title>Project Objectives</title>
10 <h1>Project Objectives</h1>
11 <p>The new frontier of Content Based Information Systems is the so called
13 <a href="./../publications/others/w3c_bl98.html">others/w3c_bl98</a>).
14 Associating meaning with content or establishing a layer of machine
15 understandable data will allow automated agents, sophisticated search
16 engines and interoperable services and will enable higher degree
17 of automation and more intelligent applications. The ultimate goal of the
18 Semantic Web is to allow machines to share and exploit knowledge in the
19 Web way, i.e. without central authority, with few basic rules, in a
20 scalable, adaptable, extensible manner. However, the actual development
21 of the Semantic Web and its technologies has been hindered so far by the
22 lack of large scale, distributed repositories of structured, content
23 oriented information. The case of Mathematical knowledge, the most
24 rigorous and condensed form of knowledge, is paradigmatic. The World Wide
25 Web is already now the largest single resource of mathematical knowledge,
26 and its importance will be exponentiated by the emerging display
27 technologies like MathML. However, almost all mathematical documents
28 available on the Web are marked up only for presentation (in this respect,
29 current practice in MathML improves on, but does not fundamentally differ
30 from the older paper-oriented markup schemes like LaTeX or Postscript).
31 A consequence of this is that the online material is machine-readable, but
32 not machine-understandable, severely crippling the possibility to offer
33 added-value services like</p>
35 <li>Preservation of the real informative content in a highly structured and
36 machine understandable format, suitable for transformation, automatic
37 elaboration and processing.</li>
38 <li>Cut and paste on the level of computation (take the output from a Web
39 search engine and paste it into a computer algebra system).</li>
40 <li>Automatic proof checking of published proofs.</li>
41 <li>Semantical search for mathematical concepts (rather than keywords).</li>
42 <li>Classification: given a concrete mathematical structure, is there a
43 general theory for it?</li>
45 <p>Due to its rich notational, logical and semantical structure, mathematical
46 knowledge is thus a main case study for the development of the new
47 generation of semantic Web systems. The aim of the proposed project is
48 both to help in this process, as well as pave the way towards a really
49 useful virtual, distributed, hyper-textual resource for the working
50 mathematician, scientist or engineer. All modern sciences have a
51 strongly mathematicised core, and will benefit. The real market and
52 application area for the techniques developed in this project, apart from
53 the obvious realm of education, lies with high-tech and engineering
54 corporations that rely on huge formula databases. Currently, both the
55 content markup as well as the added-value services alluded to above are
56 very underdeveloped, limiting the usefulness of the vital knowledge. The
57 infrastructure and knowhow needed for mining this information treasure
58 and obtaining a competitive edge in development is exactly what we are
59 attempting to develop in our project.</p>
60 <p>Several languages have been already proposed for the management of
61 mathematical information on the Web, both for publishing, communication
62 and archiving purposes: most notably,
63 <a href="http://www.w3.org/TR/MathML2/">MathML</a>,
64 <a href="http://www.nag.co.uk/projects/openmath/omsoc/">OpenMath</a>,
65 <a href="http://www.mathweb.org/omdoc/">OMDoc</a>. Other languages
66 must be also considered for definition and specification of Metadata,
67 such as the <a href="http://purl.org/dc/">Dublin Core</a> System, or
68 the Resource Description Framework
69 [<a href="http://www.w3.org/RDF/">RDF</a>].
70 All these languages, which tend to cover different and orthogonal aspects
71 of the management of mathematical documents, must be eventually taken into
72 account for the ambitious goal of our project. One of our aims is actually
73 the definition of a modular architecture which could exploit the
74 distinctive potentialities of each one of these languages, integrating
75 them into a single application. The integration is in this case
76 facilitated by the fact that all the languages mentioned are particular
77 instances of XML, providing the opportunity to use standard XML
78 technology, and in particular XSL Transformations or
79 stylesheets [<a href="http://www.w3.org/TR/xslt">XSLT</a>], to pass from
80 one language to the other.</p>
82 <img border="0" alt="Architecture" src="./../../images/arch.png" />
84 <p>The fact of encoding also the microscopic, logical level of mathematics
85 opens the possibility to have completely formalised subsystems of the
86 library, which could be checked automatically by standard tools for the
87 automation of formal reasoning and the mechanisation of mathematics
88 (proof assistants and logical frameworks, see
89 <a href="./../publications/others/cup_hp91.html">others/cup_hp91</a> and
90 <a href="./../publications/others/cup_hp93.html">others/cup_hp93</a>). At
91 the same time, any of these tools could be used as an authoring system for
92 documents of the library, by simply exporting their internal libraries
93 into XML, and using stylesheets to transform the output into a standard,
94 machine-understandable representation, such as MathML content markup or
96 <p>The precise formal content can still be preserved by the machinery of
97 <a href="http://www.w3.org/TR/xlink/">Xlinks</a>. Moreover, stylesheets
98 can be also used to solve the annoying notational problem that usually
99 afflicts formal mathematics, providing a simple way for adding
100 user-defined styles and notations.</p>
102 <p>So, our approach leads to a natural integration of proof assistant tools
103 and the Web. In this integration, the emphasis is just on ``content'':
104 we do not try to link directly the specific applications to the Web,
105 that would be a major mistake, for obvious modularity reasons. On the
106 contrary, we adopt XML as a neutral specification language, and then we
107 merely work on XML-documents, forgetting the underlying application. In
108 this way, similar software tools can be applied to different logical
109 dialects, regardless of their concrete nature. Moreover, if having a
110 common representation layer is not the ultimate solution to all
111 inter-operability problems between different applications, it is
112 however a first and essential step in this direction. Finally, this
113 ``standardisation'' process should naturally lead to a substantial
114 simplification and re-organisation of the current, ``monolithic''
115 architecture of logical frameworks. All the many different and often
116 loosely connected functionalities of these complex programs (proof
117 checking, editing, search and consulting, program extraction, and so on)
118 could be clearly split in more or less autonomous tasks, and could be
119 developed by different teams, in totally different languages. This is
120 the new, ``content-based'' architectural design of future systems.</p>