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fix #2548 fix #2530

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2019-09-13 13:54:51 +02:00
parent 5d9ed5b0a9
commit 67c4777514
11 changed files with 251 additions and 126 deletions
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43
src/muz/spacer/spacer_arith_generalizers.cpp
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@ -45,48 +45,7 @@ struct limit_denominator_rewriter_cfg : public default_rewriter_cfg {
}
bool limit_denominator(rational &num) {
rational n, d;
n = numerator(num);
d = denominator(num);
if (d < m_limit) return false;
/*
Iteratively computes approximation using continuous fraction
decomposition
p(-1) = 0, p(0) = 1
p(j) = t(j)*p(j-1) + p(j-2)
q(-1) = 1, q(0) = 0
q(j) = t(j)*q(j-1) + q(j-2)
cf[t1; t2, ..., tr] = p(r) / q(r) for r >= 1
reference: https://www.math.u-bordeaux.fr/~pjaming/M1/exposes/MA2.pdf
*/
rational p0(0), p1(1);
rational q0(1), q1(0);
while (d != rational(0)) {
rational tj(0), rem(0);
rational p2(0), q2(0);
tj = div(n, d);
q2 = tj * q1 + q0;
p2 = tj * p1 + p0;
if (q2 >= m_limit) {
num = p2 / q2;
return true;
}
rem = n - tj * d;
p0 = p1;
p1 = p2;
q0 = q1;
q1 = q2;
n = d;
d = rem;
}
return false;
return rational::limit_denominator(num, m_limit);
}
br_status reduce_app(func_decl *f, unsigned num, expr *const *args,