- Alonso Church
- Formalization of computation.
- Similar to Turing machine
- Used to maintain state
- return to caller is a special case of continuations
def make_incr
n=0
lambda{ n = n + 1}.curry
end
incr1 = make_incr
incr2 = make_incr
incr1.() #=> 1
incr2.() #=> 1
incr1.() #=> 2
incr1.() #=> 3
incr2.() #=> 2