The following cmavo are discussed in this section:

Lojban possesses a special category of selbri which are based on mekso. The simplest kind of such selbri are made by suffixing a member of selma'o MOI to a number. There are five members of MOI, each of which serves to create number-based selbri with specific place structures.

The cmavo mei creates cardinal selbri. The basic place structure is:

A cardinal selbri interrelates a set with a given number of members, the mass formed from that set, and the individuals which make the set up. The mass argument is placed first as a matter of convenience, not logical necessity.

Some examples:

Here, the mass of my rats is said to have three components; that is, I have three rats.

Another example, with one element this time:

In Example 18.82, mi refers to a mass, “the mass consisting of me”. Personal pronouns are vague between masses, sets, and individuals.

However, when the number expressed before -mei is an objective indefinite number of the kind explained in Section 18.8, a slightly different place structure is required:

An example:

In Example 18.83, the x2 and x3 places are vacant, and the x4 place is filled by lo'i ratcu, which (because no quantifiers are explicitly given) means “the whole of the set of all those things which are rats”, or simply “the set of all rats.”

In Example 18.84, the conversion cmavo se swaps the x1 and the x2 places, so that the new x1 is the set. The x4 set is unspecified, so the implication is that the rats are “many” with respect to some unspecified comparison set.

More explanations about the interrelationship of sets, masses, and individuals can be found in Section 6.3.

The cmavo moi creates ordinal selbri. The place structure is:

Some examples:

Example 18.87 means, in the appropriate context, that my position in line is sufficiently far to the front that I will get a seat for the movie.

The cmavo si'e creates portion selbri. The place structure is:

Some examples:

The cmavo cu'o creates probability selbri. The place structure is:

The number must be between 0 and 1 inclusive. For example:

The cmavo va'e creates a scale selbri. The place structure is:

If the scale is granular rather than continuous, a form like cifi'uxa (3/6) may be used; in this case, 3/6 is not the same as 1/2, because the third position on a scale of six positions is not the same as the first position on a scale of two positions. Here is an example:

When the quantifier preceding any MOI cmavo includes the subjective numbers rau, du'e, or mo'a (enough, too many, too few) then an additional place is added for “by standard”. For example:

The extra place (which for -mei is the x4 place labeled by fo) is provided rather than using a BAI tag such as ma'i because a specification of the standard for judgment is essential to the meaning of subjective words like “enough”.

This place is not normally explicit when using one of the subjective numbers directly as a number. Therefore, du'e ratcu means “too many rats” without specifying any standard.

It is also grammatical to substitute a lerfu string for a number:

More complex mekso cannot be placed directly in front of MOI, due to the resulting grammatical ambiguities. Instead, a somewhat artificial form of expression is required.

The cmavo me (of selma'o ME) has the function of making a sumti into a selbri. A whole me construction can have a member of MOI added to the end to create a complex mekso selbri:

Here the mekso ny. su'i pa is made into a sumti (with li) and then changed into a mekso selbri with me and me'u moi. The elidable terminator me'u is required here in order to keep the pa and the moi separate; otherwise, the parser will combine them into the compound pamoi and reject the sentence as ungrammatical.

It is perfectly possible to use non-numerical sumti after me and before a member of MOI, producing strange results indeed:

Note: the elidable terminator boi is not used between a number and a member of MOI. As a result, the me'u in Example 18.93 could also be replaced by a boi, which would serve the same function of preventing the pa and moi from joining into a compound.