[λ] /prog/ challenge -1 [λ]
Name:
Anonymous
2012-08-07 19:21
Write a function f where for any integer x, x + 1 = f(f(f(x))), but x, f(x) and f(f(x)) are mutually different.
Name:
(λ λ λ)
2012-08-07 19:25
(define (f x) (+ x 1/3))
Name:
Anonymous
2012-08-07 19:37
>>1
that requires first defining what
(x, y) + 1 does.
Name:
Anonymous
2012-08-07 19:48
>>3
You definitely misread that.
Name:
Anonymous
2012-08-07 19:51
x, x + 1 = f(f(f(x)))
Here you have f returning a tuple of two values. Since you compose f with itself, x must be a tuple of two values.
Name:
Anonymous
2012-08-07 22:27
(defun f (x)
(cond ((numberp x) (write-to-string x))
((stringp x) (intern x))
(t (1+ (read-from-string (symbol-name x))))))
Name:
Anonymous
2012-08-08 2:40
mutually different is jew doublespeak
Name:
Anonymous
2012-08-08 5:53
>>3
According to the standard rules
*,
(x, y) + 1 = (x + 1, y + 1) By the way, note that x and y must be pairs themselves.
___________
[*] http://en.wikipedia.org/wiki/Surreal_numbers
Name:
Anonymous
2012-08-08 8:02
I think
>>1 means this:
∀
x∈Z:
x+1=f(f(f(
x))) ∧
x≠f(
x) ∧
x≠f(f(
x)) ∧ f(
x)≠f(f(
x))
Name:
Anonymous
2012-08-08 9:03
i don't get it
Name:
>>1
2012-08-08 12:43
>>9
I do. There are no code tags on that comma, it's not part of the equations surrounding it.
Name:
Anonymous
2012-08-08 19:34
>>9
People can hate the syntax all day, but this is unambiguous.