+/* This checks whether subs() works as intended in some special cases. */
+static unsigned exam_subs()
+{
+ unsigned result = 0;
+ symbol x("x");
+ ex e1, e2;
+
+ // This used to fail in GiNaC 1.0.5 because it first substituted
+ // x+1 -> (x-1)+1 -> x, and then substituted again x -> x-1, giving
+ // the wrong result
+ e1 = x+1;
+ e2 = e1.subs(x == x-1);
+ if (!e2.is_equal(x)) {
+ clog << "(x+1).subs(x==x-1) erroneously returned " << e2 << " instead of x" << endl;
+ ++result;
+ }
+
+ e1 = sin(1+sin(x));
+ e2 = e1.subs(sin(wild()) == cos(wild()));
+ if (!e2.is_equal(cos(1+cos(x)))) {
+ clog << "sin(1+sin(x)).subs(sin($1)==cos($1)) erroneously returned " << e2 << " instead of cos(1+cos(x))" << endl;
+ ++result;
+ }
+
+ return result;
+}
+
+/* Joris van der Hoeven (he of TeXmacs fame) is a funny guy. He has his own
+ * ideas what a symbolic system should do. Let's make sure we won't disappoint
+ * him some day. Incidentally, this seems to always have worked. */
+static unsigned exam_joris()
+{
+ unsigned result = 0;
+ symbol x("x");
+
+ ex e = expand(pow(x, x-1) * x);
+ if (e != pow(x, x)) {
+ clog << "x^(x-1)*x did not expand to x^x. Please call Joris!" << endl;
+ ++result;
+ }
+
+ return result;
+}
+
+/* Test Chris Dams' algebraic substitutions. */
+static unsigned exam_subs_algebraic()
+{
+ unsigned result = 0;
+ symbol x("x"), y("y");
+
+ ex e = ex(x*x*x*y*y).subs(x*y==2, subs_options::subs_algebraic);
+ if (e != 4*x) {
+ clog << "(x^3*y^2).subs(x*y==2,subs_options::subs_algebraic) erroneously returned " << e << endl;
+ ++result;
+ }
+
+ e = ex(x*x*x*x*x).subs(x*x==y, subs_options::subs_algebraic);
+ if (e != y*y*x) {
+ clog << "x^5.subs(x^2==y,subs_options::subs_algebraic) erroneously returned " << e << endl;
+ ++result;
+ }
+
+ return result;
+}
+
+unsigned exam_misc()