Chapter 18: lojbau mekso: Mathematical Expressions in Lojban
20. Explicit operator precedence
As mentioned earlier, Lojban does provide a way for the precedences of operators to be explicitly declared, although current parsers do not understand these declarations.
The declaration is made in the form of a metalinguistic comment using “ti'o”, a member of selma'o SEI. “sei”, the other member of SEI, is used to insert metalinguistic comments on a bridi which give information about the discourse which the bridi comprises. The format of a “ti'o” declaration has not been formally established, but presumably would take the form of mentioning a mekso operator and then giving it either an absolute numerical precedence on some pre-established scale, or else specifying relative precedences between new operators and existing operators.
In future, we hope to create an improved machine parser that can understand declarations of the precedences of simple operators belonging to selma'o VUhU. Originally, all operators would have the same precedence. Declarations would have the effect of raising the specified cmavo of VUhU to higher precedence levels. Complex operators formed with “na'u”, “ni'e”, or “ma'o” would remain at the standard low precedence; declarations with respect to them are for future implementation efforts. It is probable that such a parser would have a set of “commonly assumed precedences” built into it (selectable by a special “ti'o” declaration) that would match mathematical intuition: times higher than plus, and so on.