The following cmavo is discussed in this section:

The cmavo du has the place structure:

and appears in selma'o GOhA for reasons of convenience: it is not a pro-bridi. du serves as mathematical “=”, and outside mathematical contexts is used for defining or identifying. Mathematical examples may be found in Chapter 18.

The main difference between

and

is this defining nature. Example 7.74 presumes that the speaker is responding to a request for information about what ko'a refers to, or that the speaker in some way feels the need to define ko'a for later reference. A bridi with du is an identity sentence, somewhat metalinguistically saying that all attached sumti are representations for the same referent. There may be any number of sumti associated with du, and all are said to be identical.

Example 7.75, however, predicates; it is used to make a claim about the identity of ko'a, which presumably has been defined previously.

Note: du historically is derived from dunli, but dunli has a third place which du lacks: the standard of equality.