FeynCalc manual (development version)

DeclareFCTensor

DeclareFCTensor[a, b, ...] declares a,b, … to be tensor heads, i.e., DataType[a,b, ..., FCTensor] is set to True.

See also

Overview, ExpandScalarProduct, Uncontract.

Examples

ClearAll[myTens] 
 
DeclareFCTensor[myTens] 
 
ExpandScalarProduct[myTens[z, Momentum[a + b], Momentum[c + d]]]

\text{myTens}\left(z,\overline{a},\overline{c}\right)+\text{myTens}\left(z,\overline{a},\overline{d}\right)+\text{myTens}\left(z,\overline{b},\overline{c}\right)+\text{myTens}\left(z,\overline{b},\overline{d}\right)

UnDeclareFCTensor[myTens]