Haycat2009 wrote: ↑September 4th, 2023, 11:48 pm
Are there any spaceships that work in both B35/S23 and B3/S23?
With a moderately weird setup LLSSS can search for ships that are shared* between the two rules. With further weirdness it can search for arbitrary width ships. When such a search terminates with no results it shows, barring bugs, that there are no (finite) ships at all. This was easily and quickly the case for c/2, c/3, 2c/4, and 2c/5.
On the other hand, c/4, c/5, c/4d, and c/5d did not complete with 8G of RAM, but what little poking I've done so far for finite widths hasn't turned up anything so the jury is still out.
Perhaps more results later when I have more RAM available to allocate to the question or when more searches at finite width have completed.
*My definition of "shared" here is the strictest possible, namely that not only is the collection of cell coordinates the same in one generation, but the evolution through all generations is identical (and therefore at no point is the absence/presence of B5 used). Contrast with a weaker definition where one generation must match but intervening generations could proceed differently as long as they looped back around to the same matching generation.