18.7. Other useful selbri for mekso bridi

So far our examples have been isolated mekso (it is legal to have a bare mekso as a sentence in Lojban) and equation bridi involving du. What about inequalities such as x < 5? The answer is to use a bridi with an appropriate selbri, thus:

Example 18.38. 

lixy.mlecalimu
The-numberxis-less-thanthe-number5.

Here is a partial list of selbri useful in mathematical bridi:

dux1 is identical to x2, x3, x4, ...
dunlix1 is equal/congruent to x2 in/on property/quality/dimension/quantity x3
mlecax1 is less than x2
zmadux1 is greater than x2
dubjavme'ax1 is less than or equal to x2 [du ja mleca, equal or less]
dubjavmaux1 is greater than or equal to x2 [du ja zmadu, equal or greater]
tamdu'ix1 is similar to x2 [tarmi dunli, shape-equal]
turdu'ix1 is isomorphic to x2 [stura dunli, structure-equal]
cmimax1 is a member of set x2
gripaux1 is a subset of set x2 [girzu pagbu, set-part]
na'ujbix1 is approximately equal to x2 [namcu jibni, number-near]
terci'ex1 is a component with function x2 of system x3

Note the difference between dunli and du; dunli has a third place that specifies the kind of equality that is meant. du refers to actual identity, and can have any number of places:

Example 18.39. 

py.duxy.boizy.
pis-identical-toxz
p = x = z

Lojban bridi can have only one predicate, so the du is not repeated.

Any of these selbri may usefully be prefixed with na, the contradictory negation cmavo, to indicate that the relation is false:

Example 18.40. 

liresu'irenadulimu
the-number2+2is-notequal-tothe-number5.
2 + 2 ≠ 5

As usual in Lojban, negated bridi say what is false, and do not say anything about what might be true.