rtoy
commented
5 days ago Imported from SourceForge on 2024-07-04 21:16:14 Created by vttoth on 2009-09-10 13:17:53 Original: https://sourceforge.net/p/maxima/bugs/1758/#0f05
- assigned_to: nobody --> vttoth
Imported from SourceForge on 2024-07-04 21:16:13 Created by *anonymous on 2009-09-10 12:32:43 Original: https://sourceforge.net/p/maxima/bugs/1758
Command 'tentex()' return a faild TeX representation for tensor product of same tensors. Exactly, for tensor with same identificators (A) and covariant indexies it generates:
tentex(A([-i,-k,a,b,c,],[])*A([-j,-l,a,b,c,],[])); $$A_{a\,b\,c}^{j\,l+i\,k}$$
- tentex is behaving like, when A is function (apply rules for product), but this don't correct for tensors.
Correctly is this form: $$A^{i\,k}_{a\,b\,c}A^{j\,l}_{a\,b\,c}$$
And more: tentex also don't respect contravariant versus covarient indexies position: For example: tentex(A[a,-b,c],[])); $$A_{a\,c}^{b}$$ but it isn't corect (for not symetric tensors). TeX out for this case must be: $$A_{a\phantom{M}c}^{\phantom{M}b}$$ ---