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// ---------------------------------------------------------------- // $Id: evaluator.tex,v 1.7 1999/09/29 12:28:26 schreine Exp $ // functions over the reals // // (c) 1999, Wolfgang Schreiner, see file COPYRIGHT // http://www.risc.uni-linz.ac.at/software/formal // ---------------------------------------------------------------- read real; read function; // is B upper/lower bound of s in first n members of sequence s? pred isUpperBound(B, s, n) <=> forall(i in nat(0, n): <=R(apply(s, i), B)); pred isLowerBound(B, s, n) <=> forall(i in nat(0, n): <=R(B, apply(s, i))); // supremum/infimum of s considering only the first n members fun sup(s, n) = such(U in range(s): and(isUpperBound(U, s, n), forall(U' in range(s): implies(isUpperBound(U', s, n), <=R(U, U')))), U); fun inf(s, n) = such(L in range(s): and(isLowerBound(L, s, n), forall(L' in range(s): implies(isLowerBound(L', s, n), <=R(L', L)))), L); // ---------------------------------------------------------------- // $Id: evaluator.tex,v 1.7 1999/09/29 12:28:26 schreine Exp $ // ----------------------------------------------------------------