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7.5.14.0. extendWeyl
Procedure from library dmodloc.lib (see dmodloc_lib).
- Usage:
- extendWeyl(S); S string or list of strings
- Assume:
- The basering is the n-th Weyl algebra over a field of
characteristic 0 and for all 1<=i<=n the identity
var(i+n)*var(i)=var(i)*var(i+1)+1 holds, i.e. the sequence of
variables is given by x(1),...,x(n),D(1),...,D(n), where D(i)
is the differential operator belonging to x(i).
- Return:
- ring, Weyl algebra extended by vars given by S
Example:
| | LIB "dmodloc.lib";
ring @D2 = 0,(x,y,Dx,Dy),dp;
def D2 = Weyl();
setring D2;
def D3 = extendWeyl("t");
setring D3; D3;
==> // coefficients: QQ
==> // number of vars : 6
==> // block 1 : ordering dp
==> // : names t x y Dt Dx Dy
==> // block 2 : ordering C
==> // noncommutative relations:
==> // Dtt=t*Dt+1
==> // Dxx=x*Dx+1
==> // Dyy=y*Dy+1
list L = "u","v";
def D5 = extendWeyl(L);
setring D5;
D5;
==> // coefficients: QQ
==> // number of vars : 10
==> // block 1 : ordering dp
==> // : names u v t x y Du Dv Dt Dx Dy
==> // block 2 : ordering C
==> // noncommutative relations:
==> // Duu=u*Du+1
==> // Dvv=v*Dv+1
==> // Dtt=t*Dt+1
==> // Dxx=x*Dx+1
==> // Dyy=y*Dy+1
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