}
+/** Resultant of two expressions e1,e2 with respect to symbol s.
+ * Method: Compute determinant of Sylvester matrix of e1,e2,s. */
+ex resultant(const ex & e1, const ex & e2, const ex & s)
+{
+ const ex ee1 = e1.expand();
+ const ex ee2 = e2.expand();
+ const int h1 = ee1.degree(s);
+ const int l1 = ee1.ldegree(s);
+ const int h2 = ee2.degree(s);
+ const int l2 = ee2.ldegree(s);
+
+ const int msize = h1 + h2;
+ matrix m(msize, msize);
+
+ for (int l = h1; l >= l1; --l) {
+ const ex e = ee1.coeff(s, l);
+ for (int k = 0; k < h2; ++k)
+ m(k, k+h1-l) = e;
+ }
+ for (int l = h2; l >= l2; --l) {
+ const ex e = ee2.coeff(s, l);
+ for (int k = 0; k < h1; ++k)
+ m(k+h2, k+h2-l) = e;
+ }
+
+ return m.determinant();
+}
+
+
} // namespace GiNaC