Language eXtensions for Scientific Computation provide all features indispensable for modern numerical software development, such as : - Operator concept (user-defined operators) - Overloading concept - Module concept - Dynamic arrays - Controlled rounding - Predefined arithmetic data types real, (extended real), complex, interval, complex interval, and corresponding vector and matrix types - Predefined arithmetic operators of highest accuracy for the arithmetic data types - Predefined elementary functions of highest accuracy for the arithmetic data types - Data type dotprecision for the exact representation of dot products - Library of mathematical problem-solving routines with automatic result verification and high accuracy