FCLoopMixedIntegralQ[exp]
returns True
if
the integral contains both Lorentz and Cartesian indices and
momenta.
[FVD[p, mu] CFAD[q, q - p]]
FCI
[%] FCLoopMixedIntegralQ
\frac{p^{\text{mu}}}{(q^2-i \eta ).((q-p)^2-i \eta )}
\text{True}
[FVD[p, mu] FAD[q, q - p]]
FCI
[%] FCLoopMixedIntegralQ
\frac{p^{\text{mu}}}{q^2.(q-p)^2}
\text{False}