Sabigi

出处：《Chromatic Homotopy Theory》 · 第 0 页

“教材标题即 Chromatic Homotopy Theory”

出处：《一般拓扑学基础》 · 第 85 页

“设 $\sqsubseteq$ 是集 $D$ 是的预序. 称 $(D,\sqsubseteq)$是定向集若 $D\ne \varnothing$ 并且对任意 $d_1,d_2\in D$, 总是存在 $d_3\in D$ 满足 $d_1\sqsubseteq d_3, d_2\sqsubseteq d_3$.”

出处：《A Concise Course in Algebraic Topology》 · 第 197 页

“Giving the universal oriented n-plane bundle over $BSO(n)$the $R$-orientation induced by its integral orientation, this defines the Euler class $e ∈ H_n (BSO(n); R)$.”

出处：《A Concise Course in Algebraic Topology》 · 第 191 页

“For $n$-plane bundles ξ over base spaces $B$, $n ≥ 0$, there are characteristic classes $w_i (ξ) ∈ H i(B; Z2), i ≥ 0$, called the Stiefel-Whitney classes. They satisfy and are uniquely characterized by the following axioms.”