# [Maxima] How to simplify kdelta?

Valery Pipin pip at iszf.irk.ru
Thu Jun 12 04:59:22 CDT 2008

```Nicola Cabibbo wrote:
> Just trying to learn Maxima, with the commands:
>
> 	if get('itensor, 'version)=false then load (itensor) ;
> 	idim(3);
> 	dim:3;
> 	defcon(q,q,qq);
> 	expr:'levi_civita([i,k,m],[])*'levi_civita([],[i1,k,m])*q([],
> [i])*q([i1],[])\$
> 	ishow(contract(expand(lc2kdt(expr))));
>
> I obtain " 5*qq-kdelta*qq ". This is correct with kdelta=3, but
> how can I directly obtain the simplified result "2 qq"?
Maxima 5.15.0 http://maxima.sourceforge.net
Using Lisp SBCL 1.0.12
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1)        if get('itensor, 'version)=false then load (itensor) ;
idim(3);
dim:3;
defcon(q,q,qq);
expr:'levi_civita([i,k,m],[])*'levi_civita([],[i1,k,m])*q([],
[i])*q([i1],[])\$
STYLE-WARNING: redefining \$NAME in DEFUN
STYLE-WARNING: redefining DERIV in DEFUN
STYLE-WARNING: redefining SDIFF in DEFUN
STYLE-WARNING: redefining \$DECSYM in DEFUN
STYLE-WARNING: redefining \$CANFORM in DEFUN
(%o1)         /usr/share/maxima/5.15.0/share/tensor/itensor.lisp
(%i2) (%o2)                                done
(%i3) (%o3)                                  3
(%i4) (%o4)                                done
(%i5)
(%i6)         ishow(contract(expand(lc2kdt(expr))));
(%t6)                          5 qq - kdelta qq
(%o6)              5 qq([], []) - kdelta([], []) qq([], [])
(%i7) ev(%,kdelta);
(%o7)                            2 qq([], [])
>
> Thanks for the attention
>
> PS: my setup is (on a Mac)
>
> wxMaxima 0.7.5 http://wxmaxima.sourceforge.net
> Maxima 5.15.0 http://maxima.sourceforge.net
> Using Lisp CMU Common Lisp Snapshot 2008-03 (19E)
>
>
>
>
>
> _______________________________________________
> Maxima mailing list
> Maxima at math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima

```