abstractor: abstractor to create logically quantified selbri variable to be used in predicate logic of third or higher order.
zo'e and da are free and bound variables of predicate logic of first order respectively; co'e and bu'a are free and bound selbri variables of predicate logic of second order respectively; in order to express predicate logic of third or higher order, it is essential to have selbri that treat selbri variables in the domain of all selbri of second order. su'u and bu'ai in selma'o NU can compose respectively free and bound selbri variables in the domain of all selbri of second order. In the case that bu'ai takes plural number of selbri variables, connect them with ju'e or something. Higher order is also possible by nesting bu'ai. Example: su'o bu'ai xe'u kei su'o bu'a ro da zo'u bu'ai da bu'a (This xe'u is an abstraction-variable-indicator-brivla used in order to put a word of selma'o NU in prenex.) See also su'u, bu'a; xe'u.