SpinorChainEvaluate[exp] explicitly evaluates suitable spinor chains, i.e. it replaces a DOT[Spinor[...],...,Spinor[...]] with a scalar quantity without a DOT.
ex = SpinorUBar[p, m] . SpinorU[p, m]
SpinorChainEvaluate[ex]\bar{u}(p,m).u(p,m)
2 m
SpinorChainEvaluate[ex, DiracSpinorNormalization -> "Nonrelativistic"]\frac{m}{p^0}
SpinorChainEvaluate[ex, DiracSpinorNormalization -> "Rest"]1
ex = SpinorUBarD[p, m] . GA[5] . SpinorUD[p, m]
SpinorChainEvaluate[ex]\bar{u}(p,m).\bar{\gamma }^5.u(p,m)
0
FCSetDiracGammaScheme["BMHV"]
SpinorChainEvaluate[ex]\text{BMHV}
(\varphi (p,m)).\bar{\gamma }^5.(\varphi (p,m))