Ian07 wrote:Probably a dumb question but how do you synthesize these two LWSSes?

...

No matter what I try, there's always gliders crossing paths.

I'm not sure there's a way to do those two with six gliders, but two copies of one of the standard one-sided syntheses will certainly work --

`x = 31, y = 39, rule = B3/S23`

26bo$25bo$25b3o8$3bobo$4b2o$4bo3$15b2o$15b2o8$14b2o$14b2o2$29bo$28b2o$

28bobo7$b2o$obo$2bo!

-- and probably there's something with seven gliders. I haven't hunted really hard for six-glider options; this was just a check that there's no problem at 8G.

EDIT: Oops, well, there's no problem at 6G either:

`x = 48, y = 62, rule = B3/S23`

o$b2o$2o31$41bo$40bo$40b3o3$45b3o$45bo$46bo2$4b2o$5b2o$4bo10$12bo$12b

2o$11bobo3$36b3o$36bo$37bo!

Start with a simultaneous construction (which doesn't work because of signal crossings _and_ interference between construction envelopes):

`x = 13, y = 16, rule = B3/S23`

7b2o$7bobo$obo4bo$b2o$bo3bo$5b2o$4bobo3$4b2o$5b2o$4bo5bo$10bobo$6b2o2b

2o$6bobo$6bo!

Every time you move all the gliders in a recipe backward by one cell, you have to move the construction site upwards by two cells (the LWSS moves at c/2 and is being constructed 4 ticks later).

You can't move the lower gliders backward, because that just makes the interference between construction envelopes worse. So instead you move the three upper gliders backwards, until the columns containing upper crossing gliders aren't within two cells horizontally of the corresponding lower crossing gliders. (You can get a tick closer than that rule allows, but 2 cells of clearance is safe if the crossing gliders are mirror images, as they are in this case.)