CurExt, Typesetting Variable-Sized Curved Symbols

The main goal of this contribution is to present a program that allows the composition of variablesized curved symbols such as those occurring in mathematics. This application, called CurExt, extends the capabilities of the well-known TEX system designed by D. E. Knuth for typesetting. Big delimiters, such as brackets, or special curved symbols, such as the Arabic mathematical summation symbol, can be built automatically according to the size and the shape of the concerned mathematical expression. CurExt will make it possible to stretch Arabic letters according to calligraphic rules in order to draw the kashida. It follows a useful tool for justifying texts written with the Arabic alphabet. Unlike in Latin alphabet based writing, where the justification is done through inserting small blanks among characters, cursive writing fills in the space between characters with the kashida.