An infinitely extensible p4 oscillator formed from two or more interacting anchors. There are three basic types: rusty anchor stack, shiny anchor stack, and wavy anchor stack. Compare ant stack.

rusty anchor stack

The following p4 oscillator with a minimum population of 8 cells, which can be incorporated into larger anchor stacks. So named because it is “darker” than other anchor stacks, i.e. has a higher average population.

rusty anchor stack.png

x = 8, y = 5, rule = s0/b2
3bo3bo$4bobo2$bobo$o3bo!

shiny anchor stack

The following p4 oscillator with a minimum population of 8 cells, which, unlike other anchor stacks, can be incorporated into larger anchor stacks vertically but not horizontally. So named because it is “lighter” than other anchor stacks, i.e. has a lower average population.

shiny anchor stack.png

x = 7, y = 5, rule = s0/b2
2bo3bo$3bobo2$bobo$o3bo!

wavy anchor stack

The following p4 oscillator with a minimum population of 8 cells, which can be incorporated into larger anchor stacks, and is necessary to incorporate rusty anchor stacks into larger stacks horizontally.

wavy anchor stack.png

x = 9, y = 5, rule = s0/b2
4bo3bo$5bobo2$bobo$o3bo!