We discuss the latticial structure of projection sets and antiprojection sets in Orlicz-Musielak spaces LΦ, with the distance given by modular ρΦ and classical F-norms generated by ρΦ. In particular, we show that the case of Amemiya F-norm is essentially different from others. This extends results given
for sets of best approximants by Landers and Rogge, Kilmer and Kozlowski, and Mazzone.
Section 4 , the concluding remark is included. 2 Background 2.1 FBP algorithm If f ( x , y ) and p ( t , θ ) are considered as the image slice and projectionsset, respectively, for the image reconstruction f ( x , y ) is estimated from p ( t , θ ). In