chris_c wrote:An interesting glider eater although I doubt it is very useful...

A Spartan highway robber! Not a very competent one -- it's a couple of lanes from being perfect... but it does allow a pure-Spartan version of at least one very useful conduit, RF48H:

`x = 79, y = 88, rule = LifeHistory`

35.2A$34.B2AB$34.4B$35.2B$33.2A3B$33.2A5B$20.2A11.8B$21.A6.2B5.6B$21.

A.AB2.6B.9B$22.2AB.B.17B$18.2A4.24B$17.B2AB2.27B$18.3B2.28B26.A$17.B.

B2.31B23.A.A$16.39B21.A.A$16.39B4.2B2.2B12.A$14.33BA18BD$14.33B2A17BD

BD$15.16B2A13B2A18B3DB$14.17B2A34B.D$15.9B2A12B2.27B$17.B2.3BA2BA10B

3.2B2A19B.2B$21.3B2A9B5.BA2BA12B6.3B$21.13B7.ABA12B4.4BAB$21.12B8.BA

13B3.4BABA2.2B$20.11B10.16B3.2BA2BA3B2A$19.11B11.16B3.3B2A2B.B2A$18.

10B15.13B3.AB2.5B.B$17.10B16.13B2.A.A4.2B$16.10B17.12B3.2A4.2B$15.6B.

2B2AB23.B12.B2AB$14.6B4.2A38.2A$13.6B$12.6B$11.6B$10.6B$9.2B3AB$8.5BA

$7.5BA$6.4B$5.4B26.2A$4.4B26.B2AB$3.4B27.4B$2.4B29.2B$.4B28.2A3B$3AB

29.2A5B$2.A17.2A11.8B$.A19.A6.2B5.6B$21.A.AB2.6B.9B$22.2AB.B.17B$18.

2A4.24B$17.B2AB2.27B$18.3B2.28B26.A$17.B.B2.31B23.A.A$16.39B21.A.A$

16.39B4.2B2.2B12.A$14.33BD18BD$14.33B2D17BDBD$15.16B2A13B2D18B3DB$14.

17B2A34B.D$15.9B2A12B2.27B$17.B2.3BA2BA10B3.2B2A16B.B$21.3B2A9B5.BA2B

A12B$21.13B7.ABA12B11.2A$21.12B8.BA13B7.A3.2A$20.11B10.16B5.A.A$19.

11B11.16B4.A.A$18.10B15.13B5.A$17.10B16.13B4.2A$16.10B17.12B$15.6B.2B

2AB23.B$14.6B4.2A$13.6B$12.6B$11.6B$10.6B$9.2B3AB$8.5BA$7.5BA$6.4B$5.

4B$4.4B$3.4B$2.4B$.4B$3AB$2.A$.A!

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**EDIT:** Three lanes from perfection, I should have said -- and probably the term "highway robber" is better reserved for circuits that can extract a signal. This reaction could be modified to extract a signal, but it would probably be more expensive than known mechanisms with better clearance... maybe this is just a "highway-robbing eater"? I forget if there's another standard name for from-the-side eaters as a class.

Now, we already have recipes for all orientations of the tub-with-tail eater constellation that are only slightly expensive -- and with enough searching we might be able to find edgy slow-salvo recipes for all orientations of tub-with-tails, so that they can safely be analyzed by an automatic compiler. But it's nice to see this easy-to-build variation, anyway, so it's definitely going into (my version of) the elementary conduits collection.

I bet a lot of other self-constructing circuitry uses will show up for this eater, actually -- it can safely catch one or the other of a G(n) glider pair right down to G3. So for example it allows a Spartan version of this old demultiplexer device... catching the unwanted natural glider from the Herschel-to-beehive converter always needed a tub-with-tail eater before now.

From a stable reflector by Paul Callahan, 30 April 1997:

Code: Select all

```
x = 116, y = 90, rule = LifeHistory
114.A$113.A$113.3A5$63.2A$62.A2.A$63.2A4$58.7B$57.8B$57.8B$57.8B$57.B
3D4B$57.2BD4B$57.2B3D2B$57.6B$56.7B$55.8B$54.8B$54.8B$52.2AB2.6B$51.A
.A2.7B$51.A4.6B$50.2A4.6B$56.6B$55.8B$56.8B$55.9B$55.9B$55.10B$55.5B
2A3B$55.5B2A4B3.2A$55.11B3.A$55.12BA.A$57.8B2.2A$51.2A4.7B$52.A4.6B$
52.A.AB.6B.BA$53.2AB.7BA.A$55.9B.2A3.C$56.7B6.C2B$55.8B5.B3C$52.3B2.
7B.B.4B$52.4B.13B$51.2A16B$51.2A9B2D4B$52.B.7BD2BD2B$46.2A6.8B2D3B$
31.A15.A7.11B$29.3A15.A.AB5.10B$16.A11.A19.2AB.3B.11B$16.3A9.2A20.17B
$19.A9.B20.16B$6.2A10.2A9.3B19.13B$7.A10.5B5.6B16.14B.2B$7.A.AB9.4B3.
10B11.18B2A$8.2AB.3B4.6B2.11B3.2B2.19B.B2A$10.7B.13B2A31B2.B$10.21B2A
22B.7B$11.44B.7B$10.45B2.7B$8.46B4.6B$2.B2.19B.B3.13B.4B10.7B$2.6BC
13B7.7B.B4.4B12.4B$2.6BCBC4B.6B19.4B14.5B$2.6B3C4B2.B.5B16.4B18.2A$2.
8BC4B7.2A15.4B19.A$2.12B8.A15.4B21.3A$4.3B16.3A11.4B24.A$2.4B19.A10.
4B$2.2A31.4B$3.A30.4B$3A19.2A9.4B$A20.B2AB7.4B$22.3B6.4B$21.B.B6.4B$
18.B.4B5.4B$17.2A4B2A2B.4B$17.2AB.BA2BA5B$18.B2.BABA2B$22.BA2B$22.4B$
20.A5B$19.A.A2.B$19.2A!
```

Don't know if this particular device will ever come in handy, but there are quite a few composite conduits floating around that are almost-Spartan, i.e., Spartan except for an annoying but unavoidable tub-with-tail eater. A lot of those TWITs are going to be avoidable now!

**EDIT2:** In the "useless" category, appropriate for this thread... it would have been really nice to Spartanify the old H116 conduit that currently needs either two eaters joined at the tails, or a tub-with-tail eater. Unfortunately the new Spartan eater doesn't

quite work out:

`x = 46, y = 31, rule = LifeHistory`

17.A$17.3A$20.A$19.2A4.2B$15.B3.8B$13.4B4.7B$12.6B.9B$12.6B.10B$11.

19B$10.19B$10.17B$11.15B$9.17B$7.21B$7.2BD21B3.2B2.2B$6.3BDBD4B.24BD$

7.2B3D4B2.23BDBD$6.5BD4B2.23B3DB$5.10B4.24BD$4.4B10.26B$3.4B12.22B$2.

4B13.12B5.5B$2.2A15.9B6.5BAB$3.A14.11B5.4BABA2.2B$3A16.7B.B2A5.2BA2BA

3B2A$A20.4B2.BA.A4.3B2A2B.B2A$20.B2A2B5.A3.AB2.5B.B$21.2A7.2A.A.A4.2B

$31.A.2A4.2B$29.A8.B2AB$29.2A8.2A!

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