Hook with tail

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Hook with tail
x = 5, y = 4, rule = B3/S23 obo$2obo$3bo$3b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 3 ZOOM 21 HEIGHT 400 SUPPRESS ]] [[ ZOOM 57 ]]
Pattern type Strict still life
Number of cells 8
Bounding box 5 × 4
Frequency class 20.5
Discovered by Unknown
Year of discovery 1971

Hook with tail (or snake eater) is an 8-cell still life. Despite it being reported on Lifeline early on,[1] it was for a long time the smallest still life without a well-established name.

This still life is comprised of the normally unstable hook with a normally unstable tail attached.


Main article: List of common still lifes

Hook with tail is the sixty-ninth most common still life in Achim Flammenkamp's census, being less common than loaf siamese loaf but more common than long integral[2]

It is the 69th most common still life on Adam P. Goucher's Catagolue, being less common than cis-bookend and bun but more common than loaf siamese loaf. It is the rarest still life with 8 cells, being less common than very long snake.[3]

The octo3obj database contains six collisions between a glider and a small constellation where the final pattern contains a hook with tail (with other junk).

Glider synthesis

On April 29, 2007 Dean Hickerson found a 4-glider synthesis of this still life.[4] Several known alternate syntheses can be found in Mark Niemiec's database.[5]

x = 27, y = 22, rule = B3/S23 14bo$15bo$13b3o6$2o23bo$bo21b2o$bob2o19b2o$2bobo6$24b3o$24bo$14b2o9bo$ 13bobo$15bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THEME Book ZOOM 10 AUTOSTART GPS 12 T 0 PAUSE 2 T 28 PAUSE 1 LOOP 29 ]]
A 4G synthesis[4]
(click above to open LifeViewer)

As a rock

The hook with tail can act as a rock in two ways, one using the tail like snake, the other using the hook as shown below.

x = 21, y = 21, rule = B3/S23 12b2o$12bo$9b2obo$9bobo3$10bo$o8bob2o$3o4bo$3bo3bo5bo3b2o$2bo3bo7bo3bo $2b2o3bo5bo3bo$13bo4b3o$8b2obo8bo$10bo3$9bobo$8bob2o$8bo$7b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ WIDTH 500 HEIGHT 500 ZOOM 16 GPS 7 AUTOSTART ]]
An example of the hook with tail being used as a rock in a period-14 oscillator found by Matthias Merzenich in 2014
(click above to open LifeViewer)
RLE: here Plaintext: here

Hook with tail family


2o$bo$bob2o$2bobo4$5b2o$5bobo$5bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 4 THUMBSIZE 2 AUTOSTART T 0 PAUSE 3 T 20 PAUSE 2 LOOP 21 ]]
Hitting a hook with tail with a glider in the correct orientation creates a beehive with bend nine plus a boat
(click above to open LifeViewer)

See also


  1. Robert Wainwright (September 1971). Lifeline, vol 3, page 2.
  2. Achim Flammenkamp (September 7, 2004). "Most seen natural occurring ash objects in Game of Life". Retrieved on November 8, 2009.
  3. Adam P. Goucher. "Statistics". Catagolue. Retrieved on May 5, 2023.
  4. 4.0 4.1 Dean Hickerson's 2, 3, and 4-glider syntheses pattern collection
  5. The 9 eight-bit still-lifes at Mark D. Niemiec's Life Page (download pattern file: 0/8ht.rle)

External links