Man or boy test

https://en.wikipedia.org/wiki/Man_or_boy_test

by lisper • 7 years ago

148 28 7 years ago

en.wikipedia.org

jdkee2• 7 years ago

I am about a third of the way through Knuth’s Art of Computer Programming. It is an amazing piece of work created by one man. The sheer breadth and level of complexity in the work is awe inspiring. I wish my younger self had read a copy when learning 6502 assembly in the 80s simply to understand data (information) structures.

That said, this procedure is a doozy. It reminds me of the Ackermann function but doesn't quite grow as fast (understatement).

lisper2• 7 years ago

If you like the Ackerman function you're gonna love Kruskal's tree theorem.

https://en.wikipedia.org/wiki/Kruskal%27s_tree_theorem

gonehome• 7 years ago

This essay is also great if you like this kind of thing: https://www.scottaaronson.com/writings/bignumbers.html

jdkee2• 7 years ago

Or Friedman’s SSCG function.

telesilla• 7 years ago

I'm not strong on mathematics but I've been able to enjoy the historical overview and references. I agree with you on how amazing the work is.

tempguy99992• 7 years ago

I've read the wiki page and still don't get what the big deal is about the ackermann function. Can someone explain? TIA

HNLurker2• 7 years ago

...and girls from gals

bryanrasmussen• 7 years ago

When I saw the title I thought, huh, maybe it's that thing were old prisoners threaten the young ones to see who's easy prey but no - it's a test in Algo 60 to see what compilers correctly implement recursion.

TeMPOraL2• 7 years ago

I thought it was going to be about rituals present in many cultures around the world (especially before contact with modern technological civilization) - the rites of passage from childhood to adulthood.

mikekchar2• 7 years ago

I was interested to know if I thought I could pass such a ritual. And then I was interested to know if I thought it was important for me to pass :-) Not sure I know the answer to that last one!

Lukas_Skywalker• 7 years ago

I thought it was about the test where children reach with their right hand over their head to touch the left ear - a common tongue-in-cheek test for first grade readiness.

Apparently the test has some real foundation. That the proportion of the limbs (and relative size of the head) only allows children to touch the ear at about 5 years old.

acqq• 7 years ago

The RosettaCode versions:

http://rosettacode.org/wiki/Man_or_boy_test

"Haskell

Haskell is a pure language, so the impure effects of updating k must be wrapped in the IO or ST monad (...)

On an AMD Opteron 6282 SE (1) using GHC 7.8.2 this program can compute k = 30 in 1064 s and 156.2 GiB. (2)"

"JavaScript

In Chrome we get a "Maximum call stack size exceeded" when a > 13. In Firefox we get "too much recursion" when a > 12." (Note: it should say "k" (the parameter) not "a").

---

1) 16 cores.

2) 156 GB of RAM: "159874 MB total memory in use"

ufo2• 7 years ago

I'm not super familiar with Algol but it seems that this function is not using call-by-value? In most of the translations the parameters to A are functions instead of reals.

Is this call by name or call by reference? And how would call by value look like in Algol?

kps2• 7 years ago

Call by name.

JetSetWilly• 7 years ago

Of course it is in the Online Encyclopedia of Integer Sequences: https://oeis.org/A132343

mcguire• 7 years ago

Knuth also wrote the "trip" and "trap" suites for TeX and MetaFont conformance.

https://texfaq.org/FAQ-triptrap

Man or boy test

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