  This study addresses the problem of "Circle Formation on an Infinite Grid by
Fat Robots" ($CF\_FAT\_GRID$). Unlike prior work focused solely on point robots
in discrete domain, it introduces fat robots to circle formation on an infinite
grid, aligning with practicality as even small robots inherently possess
dimensions. The algorithm, named $CIRCLE\_FG$, resolves the $CF\_FAT\_GRID$
problem using a swarm of fat luminous robots. Operating under an asynchronous
scheduler, it achieves this with five distinct colors and by leveraging
one-axis agreement among the robots.
