1. Alefeld, G. and Herzberger, J.Introduction to interval computation. Academic Press, N.Y., 1983.
2. Campos, M. A.Formalizing and implementing (or proving) properties of intervals using the OBJ3 system. Technical Report, No. 002, DI-UFPE-BR.
3. Goguen, J., Winkler, T., Meseguer, J., Futatsigi, K., and Jouannaud, J.Introduction to OBJ. Technical Report, SRI International, 1993, to appear.
4. Hammer, R., Neaga, M., and Ratz, D.Pascal-XSC, new concepts for scientific computation and numerical data processing. In: Adams, E. and Kulisch, U. (eds) “Scientific Computing with Automatic Result Verification 189”, Academic Press, 1993, pp. 15–44.
5. Kulisch, U. W. and Miranker, W. L.Computing arithmetic in theory and practice. Academic Press, 1981.