From coinductive proofs to exact real arithmetic: theory and applications

Ulrich Berger, Reinhard Kahle
2011 Logical Methods in Computer Science  
Based on a new coinductive characterization of continuous functions we extract certified programs for exact real number computation from constructive proofs. The extracted programs construct and combine exact real number algorithms with respect to the binary signed digit representation of real numbers. The data type corresponding to the coinductive definition of continuous functions consists of finitely branching non-wellfounded trees describing when the algorithm writes and reads digits. We
more » ... cuss several examples including the extraction of programs for polynomials up to degree two and the definite integral of continuous maps.
doi:10.2168/lmcs-7(1:8)2011 fatcat:xvobbwkxgfcwfjlqixqqhgmzrq