var a:={{1,2},{0,1,2}};
a[1][4]:=2;
print("sort with null entry");
print(a.sort(3));
//print(a); // disabled due to non deterministic (ptr compare)

print("sort with index too large");
print(a.sort(4));
//print(a); // see above 

print("sort strings");
a[1][4]:="bb";
a[2][4]:="aa";
print(a.sort(4));
print(a);

print("sort mixed");
a[1][5]:=5.6;
a[2][5]:=5;
print(a.sort(5));
print(a);

print("sort mixed");
a[1][6]:=5;
a[2][6]:="5a";
print(a.sort(6));
print(a);

print("sort invalid");
a.append(5);
print(a.sort(6));
print(a);

print("sort invalid");
print(a.sort(0));
print(a);

print("sort invalid");
a[3]:={};
print(a.sort(6));
print(a);

print("sort invalid");
a[3]:={1};
a[5]:={1};
print(a.sort(1));
print(a);