x1 (brivla/selbri) is used by place x2 (number/me'o+FA+bu) being filled with (a description of / symbol for) x3, in the usage of x4, according to rule(s) x5.
Property relativizing determiner / unary quantifier constructor. {kai'i} introduces a predicate whose first argument slot becomes filled by the property made by taking the bridi in which this {kai'i} appears and putting {ce'u} into the argument slot in which this {kai'i} argument was located. Put formally, "kai'i brodi cu brodu" = "lo ka ce'u brodu cu brodi". Additionally, a {kai'i} term has a rightward logical scope, like quantifiers and adverbials.