|
In category theory, string diagrams are a way of representing 2-cells in 2-categories. == Definition == The idea is to represent structures of dimension ''d'' by structures of dimension ''2-d'', using the Poincaré duality. Thus, * an object is represented by a portion of plane, * a 1-cell is represented by a vertical segment — called a ''string'' — separating the plane in two (the left part corresponding to ''A'' and the right one to ''B''), * a 2-cell is represented by an intersection of strings (the strings corresponding to ''f'' above the link, the strings corresponding to ''g'' below the link). The parallel composition of 2-cells corresponds to the horizontal juxtaposition of diagrams and the sequential composition to the vertical juxtaposition of diagrams. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「String diagram」の詳細全文を読む スポンサード リンク
|