FeynCalc manual (development version)

DeclareNonCommutative

DeclareNonCommutative[a, b, ...] declares a,b, ... to be non-commutative, i.e., DataType[a,b, ..., NonCommutative] is set to True.

See also

Overview, DataType, UnDeclareNonCommutative.

Examples

As a side effect of DeclareNonCommutative, x is declared to be of data type NonCommutative.

DeclareNonCommutative[x]

DataType[x, NonCommutative]

\text{True}

DeclareNonCommutative[y, z] 
 
DataType[a, x, y, z, NonCommutative]

\{\text{False},\text{True},\text{True},\text{True}\}

UnDeclareNonCommutative[x, y, z] 
 
DataType[a, x, y, z, NonCommutative]

\{\text{False},\text{False},\text{False},\text{False}\}