That is potentially a three step process.
1. decide how you want to represent your tensor
2. code a function that performs the product
3. use infix notation (xfy) in the bulk of the sheet
(Using the literal notation (ctrl+shift+K) to allow
the use of special characters e.g. *, dot, ...) [use
cut and paste to replicate where required, it's
quicker than typing]
Philip Oakley
[the problem is that general tensors are not that
common in everyday maths, so there isn't an accepted
notation - is a matrix just a vector tensor, or
should we use a vector of vectors for that tensor]