Opened 15 years ago

Closed 15 years ago

opposite depends on current ring

Reported by: Owned by: Oleksandr Oleksandr major 3-1-1 singular-kernel opposite, non-commutative hannes

Description

```LIB "nctools.lib";
ring R = 0, (a,b, X, Y, Z), dp;
def E = SuperCommutative(3);
def EE = opposite(E); // IN R!
setring E;E;
//   characteristic : 0
//   number of vars : 5
//        block   1 : ordering dp
//                  : names    a b X Y Z
//        block   2 : ordering C
//   noncommutative relations:
//    YX=-XY
//    ZX=-XZ
//    ZY=-YZ
// quotient ring from ideal
//_[1]=Z2
//_[2]=Y2
//_[3]=X2
var(3)*var(3); // 0
setring EE; EE; // BUG: no quotient:
//   characteristic : 0
//   number of vars : 5
//        block   1 : ordering a
//                  : names    z y x B A
//                  : weights  1 1 1 1 1
//        block   2 : ordering ls
//                  : names    z y x B A
//        block   3 : ordering C
//   noncommutative relations:
//    yz=-zy
//    xz=-zx
//    xy=-yx
var(3)*var(3); // x2 is wrong!
setring E; def EE = opposite(E); // IN E:
setring EE;EE; // correct!
//   characteristic : 0
//   number of vars : 5
//        block   1 : ordering a
//                  : names    z y x B A
//                  : weights  1 1 1 1 1
//        block   2 : ordering ls
//                  : names    z y x B A
//        block   3 : ordering C
//   noncommutative relations:
//    yz=-zy
//    xz=-zx
//    xy=-yx
// quotient ring from ideal
// _[1]=z2 // correct!
// _[2]=y2
// _[3]=x2
var(3)*var(3); // 0 -- correct
```

Changed 15 years ago by Oleksandr

my test of opposite for Exterior algebra

Changed 15 years ago by Oleksandr

results of my test of opposite for Exterior algebra: BUG!!!!!!!! (memory access!)

Changed 15 years ago by Oleksandr

at least one bug in opposite is a pure PLURAL heritage bug!

comment:1 Changed 15 years ago by Oleksandr

Version: 3-0-5

comment:2 Changed 15 years ago by Oleksandr

Resolution: → fixed new → closed

Fixed. Seems to work now. There was something messed up with quotients to sort out.

Note that the resulting ordering may become really weird!

Changed 15 years ago by Oleksandr

current ring-dependency has beed resolved somehow

without SCA

Changed 15 years ago by Oleksandr

with SCA : more intelligence :)