The Role of the Precise Definition of Stiffness in Designing Codes for the Solution of ODEs.

The notion of stiffness, which originated in several applications of different nature, has dominated the activities related to the numerical treatment of differential problems in the last fifty years. Its definition has been, for a long time, not formally precise. The needs of applications, especially those rising in the construction of robust and general purpose codes, require nowadays a formally precise definition. In this paper, we review the evolution of such notion and we provide also with a precise definition that could be used practically. [ABSTRACT FROM AUTHOR]