opposite depends on current ring

[Oleksandr]

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

[Oleksandr]

my test of opposite for Exterior algebra

[Oleksandr]

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

[Oleksandr]

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

[Oleksandr]

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

Note that the resulting ordering may become really weird!

[Oleksandr]

current ring-dependency has beed resolved somehow

[Oleksandr]

without SCA

[Oleksandr]

with SCA : more intelligence :)

[Oleksandr]

Dear Hans,

could you please check whether there is anything to be done concerning the weird resulting ring ordering?!

(please, take a look at the file "opposite.log" above)