View source for bu'ai and xe'u

{{cmavo|bu'ai|NU|Abstractor: 
abstractor: abstractor to create logically quantified selbri variable to be used in predicate logic of third or higher order. }}
See [[BPFK Section: Abstractors]], [[Experimental cmavo]], [[BPFK Section: Abstractors|su'u]], [[BPFK Section: Pro-bridi|bu'a]], '''xe'u'''.

*proposed by guskant.
[[BPFK Section: Grammatical Pro-sumti|zo'e]] and [[BPFK Section: Logical Variables|da]] are a constant and a bound variable of predicate logic of first order respectively; [[BPFK Section: Pro-bridi|co'e]] and [[BPFK Section: Pro-bridi|bu'a]] are a selbri constant and a bound selbri variable 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. [[BPFK Section: Abstractors|su'u]] in selma'o NU can compose respectively a selbri constant and a bound selbri variable in the domain of all selbri of second order. In the case that '''bu'ai''' takes plural number of selbri variables, connect them with [[BPFK Section: Non-logical Connectives|ju'e]] or something. Higher order is also possible by nesting '''bu'ai'''. 
{{mu|su'o bu'ai xe'u kei su'o bu'a ro da zo'u bu'ai da bu'a}}
'''xe'u''' is an abstraction-variable-indicator-selbrisle used in order to put a word of selma'o NU in prenex.

{{cmavo|xe'u|GOhA|Abstraction variable indicator selbrisle.}}
See [[BPFK Section: Pro-bridi|GOhA]], [[Experimental cmavo]], [[BPFK Section: Abstractors|ce'u]], '''bu'ai'''.

*proposed by guskant.
'''xe'u''' is a pro-bridi (meaning it takes the place of a fully-specified bridi). '''xe'u''' indicates that the selbrisle is considered to be a bridi-variable that can be filled by other bridi. '''xe'u''' makes sense only inside abstraction clauses. In particular, '''xe'u''' is almost solely used in prenex in order to put a word of selma'o NU in prenex in a statement of predicate logic of third or higher order. See '''bu'ai''' for usage.