JOI (http://www.lojban.org/en/publications/reference_grammar/chapter14.html)

Specifies a non-logical connection (e.g. together-with-as-mass, -set, or
-sequence) between two sumti, tanru units, or various other things. When
immediately followed by GI, provides forethought non-logical connection analogous
to GA.

la djan. joi la .alis. cu bevri le pipno John massed-with Alice carry the
piano.

