chair44 is a seven-cube chair — a 2×2×2 block with one corner knocked out —
covered in bumps and dents so that copies only mate one way.
the shape is a rep-tile: eight small chairs, each turned the right way,
build a chair twice the size. that nesting is where the aperiodicity is claimed to come from.
this page finds the eight-child dissection itself, by exact cover over the 24 cube rotations,
and checks it tiles with no gaps. only rotations are used — never a mirror copy.
the aperiodicity is a preprint claim, not a proved result. the dissection is real.