Generalizing further, consider a vector in an -dimensional vector space over the field of complex numbers , symbolically stated as .
Rather than such conventions as bold type, over arrows, and underscores (i.e., \mathbf{A},\,\vec{A},\,\underline{A}), which are used to describe vectors elsewhere in applicable fields, Dirac's notation for a vector uses vertical bars and angular brackets: |A\rangle.