jbobanido fu'ivla

x1 is a 'Lojbanido', a daughter-language (linguistic offspring, not mutually intelligible) of Lojban, used by x2 to express/communicate x3.

Also 'Lojclone'. Refers only to languages developed after the debut of Lojban and in some way built on Lojbanic priniciples. Such languages include xorban and tanbau (arguably). This word is patterned phonetically after the Esperanto word 'Esperantido', which refers to languages 'descended' from Esperanto (the word means 'Esperanto-offspring'). The -ido suffix has entered into general use in constructed-language circles (not only English- or Esperanto-speaking ones) to denote the 'offspring' of famous conlangs.