The standard notation for a state vector is a *ket vector*
|. For example, a vector in with basis
,, is typically written as

= *a* + *b* + *c* = (*a*, *b*, *c*)^{T}.

In Dirac notation, it would be written as

| *v* = *a*| *i* + *b*| *j* + *c*| *k* = (*a*, *b*, *c*)^{T}.

The term ket and this notation come from the physicist Paul Dirac who
wanted a concise way of writing formulas involving row and column
vectors. He referred to row vectors as