Step4.
Let B be a boundary such that (X, B) is eps-lc and Kx + B ~R 0.
---- 通过条件约束来“造相”.
---- 这种情况看作 “条件方程”:
(X, B) ~ eps-lc & Kx + B ~R 0.
---- B 像未知量那样存在.
(书本里肯定有个对应的存在定理).
.
Let Kv + Bv = ψ*φ*(Kx + B) and Kv + Ωv = ψ*φ*(Kx + Ω).
----“ ψ*φ* ” 可看作 “算符” 或 “单词”.
---- B 和 Ω (或 Bv 和 Ωv), 二相出, 必分伯仲...
---- 上述公式也可看作“锻法”.
.
Then (V, Bv) is sub-eps-lc and a(T, V, Bv) = a(T, X, B) ≤ 1.
---- 怎么出来的?
(暂时作为“公式”记住).
.
Similarly, (V, Ωv) is sub-lc and a(T, V, Ωv) = a(T, X, Ω) ≤ 1.
---- 同上.
.
By construction, the union of SuppΩv and the exceptional divisors of V --> X is contained in SuppΛ, hence Ωv ≤ Λ which implies a(T, V, Λ) ≤ a(T, V, Ωv) ≤ 1.
---- (SuppΩv ∪ Ev) ⊂ SuppΛ ==> Ωv ≤ Λ ==> a(T, V, Λ) ≤ a(T, V, Ωv) ≤ 1.
.
评论: 两个公式,三个不等式. 落点在 a(T, V, Λ) ≤ 1.
---- 最后一句未出现 B, 而是落到 Λ.
.
小结: Step4 读写完毕.
符号大全、上下标.|| 常用:↑↓ πΓΔΛΘΩμφΣ∈ ∉ ∪ ∩ ⊆ ⊇ ⊂ ⊃ ≤ ≥ ⌊ ⌋ ⌈ ⌉ ≠ ≡ ⁻⁺⁰ ¹ ² ³ ᵈ ₀ ₁ ₂ ₃ ᵢ .