Aspects de la problématique de la confection d’une fonte pour les mathématiques arabes

Lazrek, Azzeddine

Cahiers GUTenberg, no. 39-40 (2001), pp. 51-62.

Ce papier relate quelques difficultés rencontrées lors de la construction d’une fonte pour les textes mathématiques arabes avec expressions symboliques composées de symboles spécifiques et orientées de droite à gauche. Ces difficultés témoignent des limites des systèmes composés pour les besoins d’une langue déterminée lorsqu’on tente de les adapter à des contextes relativement lointains.

A great deal of Arabic texts of mathematics contains formulas composed with specific symbols in a writing running from right to left. Up till now, as far as we know, there is no system that allows typesetting such documents. Millions of scholars throughout Arabic countries use handbooks where symbols are still written by hand. The system presented in this paper is an attempt to provide the possibility of typesetting such documents. The capabilities of the system TeX and of the package ArabTeX will be extended to suit with this situation. The Arabic font Naskh designed by K. Lagally for his package ArabTeX and the family Computer Modern designed by D. E. Knuth in Metafont in use in his system TeX serve as basic fonts. In mathematical mode, the font Naskh well be adapted to various sizes according to the different positions (normal, superscript or subscript, superscript of superscript, etc.). This font is used to design new signs in different shapes and for abbreviations. The family Computer Modern, especially Computer Modern Math Symbols and Computer Modern Math Extension, well help to build some special symbols via glyphs inversions. Many difficulties come up after wards. Heterogeneity of size, bold face level, the position of symbols with respect to the baseline, are some of such difficulties in symbolic writing. Shapes changes of Arabic characters between text mode and mathematical mode are further difficulties in text mode. These difficulties attest of the limits of systems composed for the needs of typesetting mathematics in a Latin Language whenever these systems are to be adapted to foreign lingual contexts.