Some interesting Nuprl Search Keys for Google.

atoms
automata
bijection
boolean
capture
connectives
coprime
correspondence
count
counting
definition
denote
empty
enumeration
equality
fibonacci
first-order
function
higher-order
identity
inequality
injection
integers
intersection
inverse
justification
length
member
mod
numerator
one-to-one
onto
pair
paradox
positive
prime
proposition
quantification
quotient
ranges
rational
recursion
recursive
remainder
russell
square
substitution
truth-values
tupling
unique
universe
variable
well-founded
witness