Dear Richard, hare is the promised patch for normal.cpp. This adds a note of clarification to the documentation for sqrfree(). Feel free to edit it at will. All the best Roberto -- Prof. Roberto Bagnara Computer Science Group Department of Mathematics, University of Parma, Italy http://www.cs.unipr.it/~bagnara/ mailto:bagnara@cs.unipr.it diff -rcp GiNaC-1.0.3.orig/ginac/normal.cpp GiNaC-1.0.3/ginac/normal.cpp *** GiNaC-1.0.3.orig/ginac/normal.cpp Thu Dec 20 12:33:43 2001 --- GiNaC-1.0.3/ginac/normal.cpp Fri Jan 18 22:09:25 2002 *************** static exvector sqrfree_yun(const ex &a, *** 1741,1751 **** return res; } ! /** Compute square-free factorization of multivariate polynomial in Q[X]. * * @param a multivariate polynomial over Q[X] * @param x lst of variables to factor in, may be left empty for autodetection ! * @return polynomial a in square-free factored form. */ ex sqrfree(const ex &a, const lst &l) { if (is_a<numeric>(a) || // algorithm does not trap a==0 --- 1741,1781 ---- return res; } ! /** Compute a square-free factorization of a multivariate polynomial in Q[X]. * * @param a multivariate polynomial over Q[X] * @param x lst of variables to factor in, may be left empty for autodetection ! * @return a square-free factorization of \p a. ! * ! * \note ! * A polynomial \f$p(X) \in C[X]\f$ is said <EM>square-free</EM> ! * if, whenever any two polynomials \f$q(X)\f$ and \f$r(X)\f$ ! * are such that ! * \f[ ! * p(X) = q(X)^2 r(X), ! * \f] ! * we have \f$q(X) \in C\f$. ! * This means that \f$p(X)\f$ has no repeated factors, apart ! * eventually from constants. ! * Given a polynomial \f$p(X) \in C[X]\f$, we say that the ! * decomposition ! * \f[ ! * p(X) = b \cdot p_1(X)^{a_1} \cdot p_2(X)^{a_2} \cdots p_r(X)^{a_r} ! * \f] ! * is a <EM>square-free factorization</EM> of \f$p(X)\f$ if the ! * following conditions hold: ! * -# \f$b \in C\f$ and \f$b \neq 0\f$; ! * -# \f$a_i\f$ is a positive integer for \f$i = 1, \ldots, r\f$; ! * -# the degree of the polynomial \f$p_i\f$ is strictly positive ! * for \f$i = 1, \ldots, r\f$; ! * -# the polynomial \f$\Pi_{i=1}^r p_i(X)\f$ is square-free. ! * ! * Square-free factorizations need not be unique. For example, if ! * \f$a_i\f$ is even, we could change the polynomial \f$p_i(X)\f$ ! * into \f$-p_i(X)\f$. ! * Observe also that the factors \f$p_i(X)\f$ need not be irreducible ! * polynomials. ! */ ex sqrfree(const ex &a, const lst &l) { if (is_a<numeric>(a) || // algorithm does not trap a==0