SBT: A Translator from Spanish Mathematical Braille to MathML

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SBT A Translator from Spanish Mathematical
Braille to MathML
Technical University of Madrid School of
Computing
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Content

• Introduction
• Related Work
• Spanish Mathematical Braille
• Ambiguities
• Mathematical Braille to MathML Translator
• Resolving Ambiguities
• Designing the Intermediate Code
• Implementing the Translator as a Library
• Developing the User Interfaces
• Conclusions

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Introduction

• Integration of blind people is a challenge
• It should start at school
• Assistive technology is of great help
• There are areas under research without suitable
  assistive technology
• Urban mobility
• Public transport
• Telephony services
• Integrated math education

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Introduction

• Integrated maths education
• Sighted people read and write mathematical signs
• Typeset Mathematical Language

• Blind people read and write mathematical signs
• Mathematical Braille

f2xgt7cos'x45cos1bX6a9
Communication Barrier
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Related Work

• Several RD projects deal with Braille
  translators
• Mathematical notation to mathematical Braille
• LaBraDoor LATEX to Marburg Braille Notation
• Math2braille architecture for building
  translators from MathML to Braille
• Mathematical Braille to mathematical notation
• Insight converts formulas from Nemeth Braille to
  LATEX
• MMBT translates from French, British and Italian
  Braille to LATEX and MathML
• Two-way translators
• Universal Maths Conversion Library library to
  support the creation of mathematical notation to
  mathematical Braille (Nemeth, Marburg, French,
  British and Italian) translators and vice versa
• Little effort in Spanish notation
• Spanish mathematical Braille translator was a
  growing need for the Spanish-speaking blind
  community

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Spanish Mathematical Braille

• June 1987, Montevideo (Uruguay)
• Representatives of the Braille presses meeting
• Agreement on the use and unification of the
  Spanish Braille notation
• Mainly with respect to mathematical symbols
• Result
• The standardisation of the Spanish Braille system
  for both basic and scientific notations
• ASCII-Braille code
• Each Braille character can be matched to an ASCII
  character

f2xgt7cos'x45cos1bx6a9
f2xgt7cos'x45cos1bx6a9
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Spanish Mathematical Braille

• Ambiguities
• Actual Braille notation raises serious problems
  of ambiguity when it is computer processed
• Blind people can use and have no problems
  interpreting the standardised mathematical
  Braille
• They can settle any doubts they may have from the
  context of the information that they are reading

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Spanish Mathematical Braille

• Ambiguities
• Text and formulas
• Some characters have different meanings depending
  on whether they appear in a text or mathematical
  formula
• Ordinal numbers
• Feminine gender of Spanish ordinal numbers
  (formed by a) and denominator of simple
  fractions
• ,gta could mean
• Enclosure signs
• Exclamation marks and speech marks
• Exclamation marks ! and add operator are
  represented by the ASCII-Braille symbol
• Speech marks " and multiply operator are
  represented by the ASCII-Braille symbol lt

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Mathematical Braille to MathML Translator

• Strategy
• Based on compiler theory
• Used a general-purpose design, which would allow
  rapid reuse of most of the translation system

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Mathematical Braille to MathML Translator

• Resolving ambiguities
• In conjunction with the Spanish National
  Organisation for the Blind (ONCE)
• They were removed by using the Braille dot 7 for
  the least common symbols
• The representation for the more frequently used
  option remains unchanged

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Mathematical Braille to MathML Translator

• Resolving ambiguities
• Text and formulas
• Special codes (_at__at_xy and _at__at_x) indicate the
  start and end of the mathematical symbology
• Ordinal numbers
• The ASCII-Braille character A (the character
  a plus dot 7) to represent feminine ordinal
  numbers
• ,gta means
• ,gtA means
• Enclosure signs
• The character plus dot 7 represents (, ,
  , , ? and ?
• Exclamation marks and speech marks
• Used dot 7 to represent exclamation (!) and
  speech marks (")
• Users can quickly and easily interpret this new
  Braille notation

10ª
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Mathematical Braille to MathML Translator

• Designing the intermediate code
• The most noteworthy module is the intermediate
  code generator, sandwiched between the analysis
  phase and code generator
• Its input is a parser tree and it outputs an
  intermediate code (designed as triples)
  independent of the source and object languages
• The triples can generally and independently
  represent the elementary operations and their
  operands
• The advantage of using the triples is that source
  or object languages can be changed easily

Intermediate Code Generation
Code Generation
Analysis
Source language
Object language
Parser tree
Triples
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Mathematical Braille to MathML Translator

• Implementing the translator as a library
• The library could be called up from different
  interfaces or applications
• Owing to the diversity of platforms on which this
  library might be needed, the requirement of
  portability to any platform equipped with a
  compiler conforming to the ANSI C standard was
  established for construction
• Result
• A C library providing a translation of a file
  in Spanish mathematical ASCII-Braille to MathML
• Developed to work in the same way on DOS, Windows
  and Linux

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Mathematical Braille to MathML Translator

• Developing the user interfaces
• Two applications were built around the Symbolic
  Braille Translator (SBT) library
• Command-line SBT
• Provides a compact tool with low memory and disk
  storage requirements to conform to the
  requirements of small portable Braille systems
• The operation involves calling the SBT by
  indicating the file to be translated and the
  output file
• The system issues a series of messages to tell
  the user what is going on at any time
• The user is also informed about any error
  detected during the translation process to
  determine what problems there are with the input
  file
• Personal computers running DOS or Linux will need
  a text-mode screen reader to allow this
  information to reach the user via voice
  synthesiser or Braille displays

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Mathematical Braille to MathML Translator

• Developing the user interfaces
• Two applications were built around the Symbolic
  Braille Translator (SBT) library
• SBT for Windows
• Provides an integral prototype for both editing
  and visually representing symbolic Braille
• It was developed in compliance with the Spanish
  standard on software accessibility UNE
  1398022003, so the blind user can operate it by
  using a screen reader

Menu to perform a range of tasks (loading a file,
translating and visualising the results,
inserting text or formulas in ASCII-Braille)
Editing area visualises the ASCII-Braille
content of the open file that can be modified by
the user
Visualisation area shows the translation results
based on the MathML file obtained by the
translator
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Conclusions

• The mathematical Braille to mathematical language
  translator system described meets the
  Spanish-speaking communitys need for
  mathematical Braille to MathML translation
• It can generate XML documents that retain the
  semantics in which the mathematical expressions
  are embedded
• This opens up a new communication channel between
  sighted and blind people, who can participate
  fully in the mathematical teaching/learning
  process

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Conclusions

• Added value able to separate the mathematical
  Braille language variant from the mathematical
  language generated by the translator
• As a result of the definition of the intermediate
  representation as triples, the creation of other
  translators using any Braille language (English
  Braille, Nemeth) to MathML would involve
  building the analysis and intermediate code
  generation phases
• Translating the Braille language to other
  mathematical notation languages (LATEX, Lambda
  Math Code), just requires a new code generator
  to translate the triples to the selected code

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Conclusions
Intermediate Code Generation
Code Generation
Spanish Braille
Analysis
MathML
Intermediate Code Generation
Code Generation
English Braille
Analysis
LATEX
Intermediate Code Generation
Code Generation
Nemeth Braille
Lambda Math Code
Analysis
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SBT A Translator from Spanish Mathematical
Braille to MathML
Technical University of Madrid School of
Computing