Arc d'X was created in 1993.
LaLa DX was created in 1985.
DX-Ball was created in 1996.
Asuka Fantasy DX was created in 1994.
Texas DX Society was created in 1970.
Super DX-Ball was created in 2004-11.
Galaga Legions DX was created on 2011-06-29.
d/dx(arctan x) = X = 1/(1 + x2)
ARC Iuridica was created in 1955.
ARC Resources was created in 1996.
Clyde Arc was created in 2006.
ARC Diversified was created in 1992.
Arc Machines was created in 1976.