John Woldemar Cowan, The Complete Lojban Language — Chapter 2 - The concept of the bridi (1997)
“ In Lojban we make no such grammatical distinctions; these three sentences, when expressed in Lojban, are structurally identical. The same part of speech is used to represent the relationship. In formal logic this whole structure is called a “predication”; in Lojban it is called a “bridi”, and the central part of speech is the “selbri”. Logicians refer to the things thus related as “arguments”, while Lojbanists call them “sumti”. These Lojban terms will be used for the rest of the book. In a relationship, there are a definite number of things being related. ”
