orientation
The concept of orientation looks so magical if we think of various formulations all describe exactly the same … 続きを読む
Algebraic Topology
common cellular structures on a topological space and their properties
Despite the cellular structure on a space is a fundamental ingredients of algebraic topology, this topic seems … 続きを読む
Grothendieck Group
To give a functor from a category of commutative monoid to the category of abelian group, namely,   … 続きを読む
H space (spanier)
Introducing H space along with the Spanier’s text Algebraic Topology. The proof in the article is basica … 続きを読む