- #1

- 842

- 3

## Main Question or Discussion Point

[tex]\partial_u \partial^u [/tex]

Isn't this like a box symbol? How is it written out again? You can write it out in 2 dimensions x,t no need to include all 3 spacial dimensions.

Isn't this like a box symbol? How is it written out again? You can write it out in 2 dimensions x,t no need to include all 3 spacial dimensions.