x1=s1 is the science/study of the Lojban/Lojbanic language based on methodology x2=s3.
This is the study of the Lojban language from any methodological or theoretical angle, not necessarily that of linguistics. The strictly linguistic study of Lojban may be distinguished as jbokembauske, while the broader, field-nonspecific study of all things Lojbanic may be distinguished as jboske.