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interval.sourceforge.net/interval/prolog/clip/clip/smath
A provably correct implementation of interval arithmetic operations and primitive constraint
contractors for the arithmetic operators (real, integer, and boolean), elementary functions
(exp,log,sin,cos,tan,asin,acos,atan,sin2pi,...).
Source code
 smath  a library of C routines for interval arithmetic and constraint narrowing
Download
Applications
 clip  a CLP(Intervals) interpreter using smath to handle constraints
Related papers

"Interval Arithmetic: from Principles to Implementation",
T. Hickey,
Q. Ju,
M.H. van Emden
JACM vol. 48, no. 5, pp 10381068, Sept. 2001,
Brandeis CS Tech. Report CS99202, 18 pp., July, 1999.

"A Unified Framework for Interval Constraints and Interval Arithmetic",
T. Hickey,
H. Wu,
M.H. van Emden
in Principles and Practice of Constraint Programming  CP98
Michael Maher and JeanFrancois Puget (eds.), SpringerVerlag,
Lecture Notes in Computer Science, v. 1520, pp. 250264, 1998

Efficient Implementation of Interval Arithmetic Narrowing Using IEEE Arithmetic
T. Hickey and
Qun Ju
unnumbered technical report,
Brandeis University, Computer Science Department,
March 1997.

Fast, Sound, and Precise Narrowing
of the Exponential Function
T. Hickey and
Qun Ju
unnumbered technical report,
Brandeis University, Computer Science Department,
March 1996.
