+// Bugs in is_polynomial (fixed 2011-05-20 and 2014-07-26).
+static unsigned exam_paranoia20()
+{
+ unsigned result = 0;
+ symbol x("x"), y("y");
+ ex e1 = sqrt(x*x+1)*sqrt(x+1);
+ if (e1.is_polynomial(x)) {
+ clog << "sqrt(x*x+1)*sqrt(x+1) is wrongly reported to be a polynomial in x\n";
+ ++result;
+ }
+ ex e2 = sqrt(Pi)*x;
+ if (!e2.is_polynomial(x)) {
+ clog << "sqrt(Pi)*x is wrongly reported to be no polynomial in x\n";
+ ++result;
+ }
+ ex e3 = sqrt(x);
+ if (!e3.is_polynomial(y)) {
+ clog << "sqrt(x) is wrongly reported to be no polynomial in y\n";
+ ++result;
+ }
+ ex e4 = (1+y)/(2+x);
+ if (e4.is_polynomial(x)) {
+ clog << "(1+y)/(2+x) is wrongly reported to be a polynomial in x\n";
+ ++result;
+ }
+ return result;
+}
+
+static unsigned is_polynomial_false_positive()
+{
+ unsigned result = 0;
+ symbol x("x"), n("n");
+ exvector nonpoly_exprs;
+ nonpoly_exprs.push_back(1/(1-x));
+ nonpoly_exprs.push_back(1/(x+1));
+ nonpoly_exprs.push_back(-1/(x-1));
+ nonpoly_exprs.push_back(1/(1-x*x));
+ nonpoly_exprs.push_back(1/(1-pow(x,n)));
+ nonpoly_exprs.push_back(x-1/(x-1));
+ for (exvector::const_iterator ep = nonpoly_exprs.begin();
+ ep != nonpoly_exprs.end(); ++ep) {
+ if (ep->is_polynomial(x)) {
+ clog << "(" << *ep << ").is_polynomial(" << x << ") "
+ "erroneously returned true" << endl;
+ ++result;
+ }
+ }
+ return result;
+}
+
+// Bug in power::expand reported by Isuru Fernando (fixed 2015-05-07).
+static unsigned exam_paranoia21()
+{
+ symbol x("x");
+ ex e = pow(x + sqrt(ex(2))*x, 2).expand();
+ if (e.nops() != 2) {
+ clog << "(x+sqrt(2)*x)^2 was wrongly expanded to " << e << "\n";
+ return 1;
+ }
+ return 0;
+}
+
+// Bug in power::expand (fixed 2015-07-18).
+static unsigned exam_paranoia22()
+{
+ symbol x("x"), y("y");
+ ex e = pow(sqrt(1+x)+y*sqrt(1+x), 2).expand();
+ if (e.nops() != 6) {
+ clog << "(sqrt(1+x)+y*sqrt(1+x))^2 was wrongly expanded to " << e << "\n";
+ return 1;
+ }
+ return 0;
+}
+
+// Bug in expairseq::evalchildren().
+static unsigned exam_paranoia23()
+{
+ unsigned result = 0;
+ symbol x("x");
+
+ epvector v1;
+ v1.push_back(expair(1, 1));
+ v1.push_back(expair(2*x, -1));
+ ex e1 = add(v1); // Should be e==1-2*x,
+ if (!e1.is_equal(1-2*x)) {
+ clog << "Failure constructing " << e1 << " from add.\n";
+ ++result;
+ }
+
+ epvector v2;
+ v2.push_back(expair(x, 1));
+ v2.push_back(expair(1,-1));
+ ex e2 = mul(v2); // Should be e==x;
+ if (!e2.is_equal(x)) {
+ clog << "Failure constructing " << e2 << " from mul.\n";
+ ++result;
+ }
+
+ return result;
+}
+
+// Bug in sqrfree_yun (fixed 2016-02-02).
+static unsigned exam_paranoia24()
+{
+ unsigned result = 0;
+ symbol x("x");
+ ex e;
+
+ e = (x-1)*(x+1) - x*x + 1; // an unexpanded 0...
+ try {
+ ex f = sqrfree(e);
+ if (!f.is_zero()) {
+ clog << "sqrfree(" << e << ") returns " << f << " instead of 0\n";
+ ++result;
+ }
+ } catch (const exception &err) {
+ clog << "sqrfree(" << e << ") throws " << err.what() << endl;
+ ++result;
+ }
+
+ e = pow(x-1,3) - expand(pow(x-1,3)); // ...still after differentiating...
+ try {
+ ex f = sqrfree(e);
+ if (!f.is_zero()) {
+ clog << "sqrfree(" << e << ") returns " << f << " instead of 0\n";
+ ++result;
+ }
+ } catch (const exception &err) {
+ clog << "sqrfree(" << e << ") throws " << err.what() << endl;
+ ++result;
+ }
+
+ e = pow(x-1,4) - expand(pow(x-1,4)); // ...and after differentiating twice.
+ try {
+ ex f = sqrfree(e);
+ if (!f.is_zero()) {
+ clog << "sqrfree(" << e << ") returns " << f << " instead of 0\n";
+ ++result;
+ }
+ } catch (const exception &err) {
+ clog << "sqrfree(" << e << ") throws " << err.what() << endl;
+ ++result;
+ }
+
+ return result;
+}
+