loj bau lujvo

b₁ is a logic language/loglang used by b₂ to express/communicate b₃=l₂ (si'o/du'u, not quote).

In notes:

lojbauske: s₁ is the science/craft-knowledge ('loglanology'/'loglangology') of logical language s₂=b₁ based on methodology s₃.
loglan: Loglan