Discrete Wilson Lines in F-Theory

Figure 3

The generating cones of the fan Σ𝐵 (yellow, outer circle), Σ_𝐵 (blue), and Σ_𝐵 (red, inner circle). By ⟨𝑖,𝑗,𝑘⟩ we denote the cone spanned by the rays number 𝑖, 𝑗, and 𝑘 in 1, and arrows mean “contained in.”