/** @file exam_paranoia.cpp
*
* This set of tests checks for some of GiNaC's oopses which showed up during
- * development. Things were evaluated wrongly and so. Such a sick behaviour
+ * development. Things were evaluated wrongly and so. Such a sick behavior
* shouldn't occur any more. But we are paranoic and we want to exclude these
* these oopses for good, so we run those stupid tests... */
/*
- * GiNaC Copyright (C) 1999-2000 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2021 Johannes Gutenberg University Mainz, Germany
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#include "exams.h"
+#include "ginac.h"
+using namespace GiNaC;
+
+#include <iostream>
+using namespace std;
// The very first pair of historic problems had its roots in power.cpp and was
// finally resolved on April 27th 1999. (Fixing the first on April 23rd
// actually introduced the second.)
-static unsigned exam_paranoia1(void)
+static unsigned exam_paranoia1()
{
unsigned result = 0;
symbol x("x"), y("y"), z("z");
// And here the second oops which showed up until May 17th 1999. It had to do
// with lexicographic canonicalization and thus showed up only if the variables
// had the names as given here:
-static unsigned exam_paranoia2(void)
+static unsigned exam_paranoia2()
{
unsigned result = 0;
symbol x("x"), y("y"), z("z");
f = e*y;
g = f - e*y;
- // After .expand(), g should be zero:
- if (!g.expand().is_zero()) {
- clog << "e = (x + z*x); f = e*y; expand(f - e*y) erroneously returned "
- << g.expand() << endl;
- ++result;
- }
// After .eval(), g should be zero:
- if (!g.eval().is_zero()) {
- clog << "e = (x + z*x); f = e*y; eval(f - e*y) erroneously returned "
- << g.eval() << endl;
- ++result;
- }
- // This actually worked already back in April 1999.
- // But we are *very* paranoic!
- if (!g.expand().eval().is_zero()) {
- clog << "e = (x + z*x); f = e*y; eval(expand(f - e*y)) erroneously returned "
- << g.expand().eval() << endl;
+ if (!g.is_zero()) {
+ clog << "e = (x + z*x); f = e*y; g = (f - e*y) erroneously returned g == "
+ << g << endl;
++result;
}
// The third bug was introduced on May 18th 1999, discovered on May 19 and
// fixed that same day. It worked when x was substituted by 1 but not with
// other numbers:
-static unsigned exam_paranoia3(void)
+static unsigned exam_paranoia3()
{
unsigned result = 0;
symbol x("x"), y("y");
<< f << endl;
++result;
}
- if (!f.eval().is_equal(y)) {
- clog << "e = x*y - y; eval(e.subs(x == 2)) erroneously returned "
- << f.eval() << endl;
- ++result;
- }
- if (!f.expand().is_equal(y)) {
- clog << "e = x*y - y; expand(e.subs(x == 2)) erroneously returned "
- << f.expand() << endl;
- ++result;
- }
return result;
}
// The fourth bug was also discovered on May 19th 1999 and fixed immediately:
-static unsigned exam_paranoia4(void)
+static unsigned exam_paranoia4()
{
unsigned result = 0;
symbol x("x");
<< g << endl;
++result;
}
- if (!g.is_zero()) {
- clog << "e = pow(x,2) + x + 1; f = pow(x,2) + x + 1; g = e-f; g.eval() erroneously returned "
- << g.eval() << endl;
- ++result;
- }
return result;
}
// The fifth oops was discovered on May 20th 1999 and fixed a day later:
-static unsigned exam_paranoia5(void)
+static unsigned exam_paranoia5()
{
unsigned result = 0;
symbol x("x"), y("y");
}
// This one was discovered on Jun 1st 1999 and fixed the same day:
-static unsigned exam_paranoia6(void)
+static unsigned exam_paranoia6()
{
unsigned result = 0;
symbol x("x");
// This one was introduced on June 1st 1999 by some aggressive manual
// optimization. Discovered and fixed on June 2nd.
-static unsigned exam_paranoia7(void)
+static unsigned exam_paranoia7()
{
unsigned result = 0;
symbol x("x"), y("y");
// This one was a result of the rewrite of mul::max_coefficient when we
// introduced the overall_coefficient field in expairseq objects on Oct 1st
// 1999. Fixed on Oct 4th.
-static unsigned exam_paranoia8(void)
+static unsigned exam_paranoia8()
{
unsigned result = 0;
symbol x("x");
// Z[X]. multiply_lcm() forgot to multiply the x-linear term with the LCM of
// the coefficient's denominators (2 in this case). Introduced on Jan 25th
// 2000 and fixed on Jan 31th.
-static unsigned exam_paranoia9(void)
+static unsigned exam_paranoia9()
{
unsigned result = 0;
symbol x("x");
// and on Feb 13th 2000 I found out that things like 2^(3/2) throw an exception
// "power::eval(): pow(0,0) is undefined" instead of simplifying to 2*2^(1/2).
// It was fixed that same day.
-static unsigned exam_paranoia10(void)
+static unsigned exam_paranoia10()
{
unsigned result = 0;
ex r;
try {
- r = pow(b,e).eval();
+ r = pow(b, e);
if (!(r-2*sqrt(ex(2))).is_zero()) {
clog << "2^(3/2) erroneously returned " << r << " instead of 2*sqrt(2)" << endl;
++result;
// add::normal() forgot to multiply the denominator of the overall_coeff of
// its expanded and normalized children with the denominator of the expanded
// child (did you get this? Well, never mind...). Fixed on Feb 21th 2000.
-static unsigned exam_paranoia11(void)
+static unsigned exam_paranoia11()
{
unsigned result = 0;
symbol x("x");
ex e = ((-5-2*x)-((2-5*x)/(-2+x))*(3+2*x))/(5-4*x);
ex f = e.normal();
- ex d = (4+10*x+8*pow(x,2))/(x-2)/(5-4*x);
+ ex d = normal((4+10*x+8*pow(x,2))/(x-2)/(5-4*x));
if (!(f - d).expand().is_zero()) {
clog << "normal(" << e << ") returns " << f << " instead of " << d << endl;
// This one returned 0 because add::normal() incorrectly assumed that if the
// common denominator is 1, all the denominators would be 1 (they can in fact
// be +/-1). Fixed on Aug 2nd 2000.
-static unsigned exam_paranoia12(void)
+static unsigned exam_paranoia12()
{
unsigned result = 0;
symbol x("x");
// This one caused a division by 0 because heur_gcd() didn't check its
// input polynomials against 0. Fixed on Aug 4th 2000.
-static unsigned exam_paranoia13(void)
+static unsigned exam_paranoia13()
{
unsigned result = 0;
symbol a("a"), b("b"), c("c");
return result;
}
-unsigned exam_paranoia(void)
+// A bug introduced on July 19, 2001. quo() and rem() would sometimes call
+// vector::reserve() with a negative argument. Fixed on Dec 20, 2001.
+static unsigned exam_paranoia14()
+{
+ unsigned result = 0;
+ symbol x("x");
+
+ ex q = quo(1, pow(x, 3), x);
+ if (!q.is_zero()) {
+ clog << "quo(1,x^3,x) erroneously returned " << q << " instead of 0\n";
+ ++result;
+ }
+
+ return result;
+}
+
+// Under certain conditions, power::expand_add_2() could produce non-canonical
+// numeric expairs. Fixed on Oct 24, 2002.
+static unsigned exam_paranoia15()
+{
+ unsigned result = 0;
+
+ ex q = (pow(pow(2, numeric(1, 2))*2+1, 2)).expand();
+ // this used to produce "1+4*sqrt(2)+4*2" which would never evaluate
+ // to "9+4*sqrt(2)"
+
+ if (!(q-9-4*pow(2, numeric(1, 2))).is_zero()) {
+ clog << "expand((sqrt(2)*2+1)^2) erroneously returned " << q << " instead of 9-4*sqrt(2)\n";
+ ++result;
+ }
+
+ return result;
+}
+
+// Expanding products containing powers of sums could return results that
+// were not fully expanded. Fixed on Dec 10, 2003.
+static unsigned exam_paranoia16()
+{
+ unsigned result = 0;
+ symbol a("a"), b("b"), c("c"), d("d"), e("e");
+ ex e1, e2, e3;
+
+ e1 = pow(1+a*sqrt(b+c), 2);
+ e2 = e1.expand();
+
+ if (e2.has(pow(a, 2)*(b+c))) {
+ clog << "expand(" << e1 << ") didn't fully expand\n";
+ ++result;
+ }
+
+ e1 = (d*sqrt(a+b)+a*sqrt(c+d))*(b*sqrt(a+b)+a*sqrt(c+d));
+ e2 = e1.expand();
+
+ if (e2.has(pow(a, 2)*(c+d))) {
+ clog << "expand(" << e1 << ") didn't fully expand\n";
+ ++result;
+ }
+
+ e1 = (a+sqrt(b+c))*sqrt(b+c)*(d+sqrt(b+c));
+ e2 = e1.expand();
+
+ if (e2.has(a*(b+c))) {
+ clog << "expand(" << e1 << ") didn't fully expand\n";
+ ++result;
+ }
+
+ e1 = pow(sqrt(a+b)+sqrt(c+d), 3);
+ e2 = e1.expand();
+
+ if (e2.has(3*(a+b)*sqrt(c+d)) || e2.has(3*(c+d)*sqrt(a+b))) {
+ clog << "expand(" << e1 << ") didn't fully expand\n";
+ ++result;
+ }
+
+ e1 = a*(b+c*(d+e));
+ e2 = e1.expand();
+
+ if (e2.has(c*(d+e))) {
+ clog << "expand(" << e1 << ") didn't fully expand\n";
+ ++result;
+ }
+
+ e1 = 2*pow(1+a, 2)/a;
+ e2 = e1.expand();
+
+ if (e2.has(pow(a, 2))) {
+ clog << "expand(" << e1 << ") didn't fully expand\n";
+ ++result;
+ }
+
+ e1 = a*(a+b);
+ e2 = pow(pow(e1, -1), -1);
+
+ if (e2.has(a*b)) {
+ clog << "double reciprocal expanded where it should not\n";
+ ++result;
+ }
+
+ return result;
+}
+
+// Bug in reposition_dummy_indices() could result in correct expression
+// turned into one with inconsistent indices. Fixed on Aug 29, 2006
+static unsigned exam_paranoia17()
+{
+ varidx mu1(symbol("mu1"), 4);
+ varidx mu2(symbol("mu2"), 4);
+ varidx mu3(symbol("mu3"), 4);
+ varidx mu4(symbol("mu4"), 4);
+ varidx mu5(symbol("mu5"), 4);
+ varidx mu6(symbol("mu6"), 4);
+
+ exvector ev2;
+ ev2.push_back(mu3.toggle_variance());
+ ev2.push_back(mu6);
+ ev2.push_back(mu5.toggle_variance());
+ ev2.push_back(mu6.toggle_variance());
+ ev2.push_back(mu5);
+ ev2.push_back(mu3);
+ // notice: all indices are contracted ...
+
+ ex test_cycl = indexed(symbol("A"), sy_cycl(), ev2);
+ test_cycl = test_cycl.simplify_indexed();
+ // ... so there should be zero free indices in the end.
+ return test_cycl.get_free_indices().size();
+}
+
+// Bug in add::eval() could result in numeric terms not being collected into
+// the overall coefficient. Fixed first on Sep 22, 2010 and again on Dec 17 2015
+static unsigned exam_paranoia18()
+{
+ unsigned result = 0;
+
+ ex sqrt2 = sqrt(ex(2));
+ ex e1 = 1 + 2*(sqrt2+1)*(sqrt2-1);
+ if (e1.real_part() != 3) {
+ clog << "real_part(1+2*(sqrt(2)+1)*(sqrt(2)-1)) failed to evaluate to 3\n";
+ ++result;
+ }
+
+ ex sqrt3 = sqrt(ex(3));
+ ex e2 = 2 + 2*(sqrt2+1)*(sqrt2-1) - 2*(sqrt3+1)*(sqrt3-1);
+ if (e2.real_part() != 0) {
+ clog << "real_part(2+2*(sqrt(2)+1)*(sqrt(2)-1)-3*(sqrt(3)+1)*(sqrt(3)-1)) failed to evaluate to 0\n";
+ ++result;
+ }
+
+ return result;
+}
+
+// Bug in mul::conjugate when factors are evaluated at branch cuts, reported as
+// Sage bug #10964.
+static unsigned exam_paranoia19()
+{
+ symbol a("a");
+ ex e = conjugate(a*sqrt(ex(-2))*sqrt(ex(-3)));
+ ex c = a*conjugate(sqrt(ex(-2)))*conjugate(sqrt(ex(-3)));
+ if (!subs(e-c, a==42).is_zero()) {
+ clog << "subs(a*conjugate(sqrt(-2))*conjugate(sqrt(-3))-conjugate(a*sqrt(-2)*sqrt(-3)),a==42) failed to evaluate to 0\n";
+ return 1;
+ }
+ return 0;
+}
+
+// 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 exam_mul_info()
+{
+ symbol x("x"), y("y");
+ ex e = x*y;
+ if (!e.info(info_flags::indefinite)) {
+ clog << "eek, product of two symbols is NOT indefinite\n";
+ return 1;
+ }
+ return 0;
+}
+
+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 add ctor
+unsigned exam_paranoia24()
+{
+ symbol a("a"), b("b"), c("c");
+ ex e = -a + 2*b + c;
+
+ if (e.diff(c).nops() > 1) {
+ clog << "diff(" << e << ",c) was not fully evaluated.\n";
+ return 1;
+ }
+ return 0;
+}
+
+// Bug in partial fraction expansion
+unsigned exam_paranoia25()
+{
+ symbol x("x");
+ ex ex1=pow(x,4)/(x-1)/4;
+ ex ex2=sqrfree_parfrac(ex1,x);
+ ex e = (ex1-ex2).normal();
+
+ if (! e.is_zero()) {
+ clog << "partial fraction expansion of " << ex1 << " produces error.\n";
+ return 1;
+ }
+ return 0;
+}
+
+// Bug in power expansion
+unsigned exam_paranoia26()
+{
+ unsigned result = 0;
+ symbol x("x"), y("y"), a("a");
+ possymbol s("s"), t("t");
+ exmap pwrs =
+ { {pow((x+1)*(y-2)*(s-3)*(t+4), a), pow((x+1)*(y-2)*(s-3), a)*pow(t+4, a)},
+ {pow(2*(x+1)*(y-2)*(s-3)*(t+4), a), pow(2,a)*pow((x+1)*(y-2)*(s-3), a)*pow(t+4, a)},
+ {pow(-(x+1)*(y-2)*(s-3)*(t+4), a), pow(-(x+1)*(y-2)*(s-3), a)*pow(t+4, a)},
+ {pow(-2*(x+1)*(y-2)*(s-3)*(t+4), a), pow(2,a)*pow(-(x+1)*(y-2)*(s-3), a)*pow(t+4, a)} };
+
+ for (auto e : pwrs) {
+ if (! (e.first.expand()).is_equal(e.second) ) {
+ clog << "power expansion of " << e.first << " produces error.\n";
+ ++result;
+ }
+ }
+
+ return result;
+}
+
+// Bug in collect()
+// cf. https://www.ginac.de/pipermail/ginac-list/2021-March/002337.html
+static unsigned exam_collect_multiply_referenced_lst()
+{
+ unsigned result = 0;
+ symbol x("x"), y("y");
+ ex a = x + y;
+ ex l = lst{x, y};
+ ex l2 = l; // make l a multiply referenced object
+
+ try {
+ ex b = collect(a, l);
+ } catch (const std::runtime_error & e) {
+ clog << "collect(" << ", " << l << ") threw a runtime_error("
+ << e.what() << ")" << endl;
+ ++result;
+ }
+
+ return result;
+}
+
+unsigned exam_paranoia()
{
unsigned result = 0;
cout << "examining several historic failures just out of paranoia" << flush;
- clog << "----------several historic failures:" << endl;
result += exam_paranoia1(); cout << '.' << flush;
result += exam_paranoia2(); cout << '.' << flush;
result += exam_paranoia11(); cout << '.' << flush;
result += exam_paranoia12(); cout << '.' << flush;
result += exam_paranoia13(); cout << '.' << flush;
-
- if (!result) {
- cout << " passed " << endl;
- clog << "(no output)" << endl;
- } else {
- cout << " failed " << endl;
- }
+ result += exam_paranoia14(); cout << '.' << flush;
+ result += exam_paranoia15(); cout << '.' << flush;
+ result += exam_paranoia16(); cout << '.' << flush;
+ result += exam_paranoia17(); cout << '.' << flush;
+ result += exam_paranoia18(); cout << '.' << flush;
+ result += exam_paranoia19(); cout << '.' << flush;
+ result += exam_paranoia20(); cout << '.' << flush;
+ result += exam_mul_info(); cout << '.' << flush;
+ result += is_polynomial_false_positive(); cout << '.' << flush;
+ result += exam_paranoia21(); cout << '.' << flush;
+ result += exam_paranoia22(); cout << '.' << flush;
+ result += exam_paranoia23(); cout << '.' << flush;
+ result += exam_paranoia24(); cout << '.' << flush;
+ result += exam_paranoia25(); cout << '.' << flush;
+ result += exam_paranoia26(); cout << '.' << flush;
+ result += exam_collect_multiply_referenced_lst(); cout << '.' << flush;
return result;
}
+
+int main(int argc, char** argv)
+{
+ return exam_paranoia();
+}