Def   == Unit+Unit

is mentioned by

Thm*  x:. is_prime(x)	[prime_decider_wf]
Thm*  !{p:()| x:. p(x)  prime(x) }	[prime_decider_exists]

In prior sections: bool 1 rel 1 quot 1 LogicSupplement

Try larger context: DiscrMathExt IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html