(a): torii with R=2 for different increasing values of μ=1,2,3 from the left to the right. When μ>R, two sheets exist: layer of type 3 takes place instead of type 2; (b): torii with μ=2 for different increasing values of R=1,2,3 from the left to the right. When R>μ, only one sheet exist: layer of type 2 takes place instead of type 3.