> (force (delay (+ 2 3)))
5
> (delay (blah blah blah))
#<promise>
> (force (delay (blah blah blah)))
[image] [image] blah: undefined;
 cannot reference an identifier before its definition
> (delay (&^ AS&D 87 AS*D& 7 ASD& 6&ASD )
         )
#<promise>
> 
> (fact 5)
120
> (define bigpromise (delay (fact 30000)))
> bigpromise
#<promise>
> (force bigpromise)
27595372462193845993799421664254627839....
> (> (force bigpromise) 0)
#t
> (> (force bigpromise) 0)
#t
> (> (force bigpromise) 0)
#t
> (> (force bigpromise) 0)
#t
> (define bigpromise (delay (fact 30000)))
> (> (force bigpromise) 0)
#t
> (define bigpromise (delay (fact 40000)))
> (> (force bigpromise) 0)
#t
> (> (force bigpromise) 0)
#t
> a
[image] [image] a: undefined;
 cannot reference an identifier before its definition
> (define undefined (delay (+ a 3)))
> (define a 10)
> (force undefined)
13
> (define undefined (delay (+ b 3)))
> (force undefined)
[image] [image] b: undefined;
 cannot reference an identifier before its definition
> (force undefined)
[image] [image] b: undefined;
 cannot reference an identifier before its definition
> (define b 20)
> (force undefined)
23
> undefined
#<promise>
> (define promise (lambda () (fact 30)))
> promise
#<procedure:promise>
> (promise)
265252859812191058636308480000000