NonCommHeadQ[exp] yields True if the head
of exp is a non-commutative object or Dot.
Overview, DataType, DeclareNonCommutative, UnDeclareNonCommutative, NonCommFreeQ, NonCommQ
NonCommHeadQ[GA[mu]]\text{True}
NonCommHeadQ[GA[mu, nu, mu]]\text{True}
NonCommHeadQ[FV[p, mu]]\text{False}
NonCommHeadQ[FCI[SUNT[a]]]\text{True}
NonCommHeadQ[FCI[SUNTF[a, i, j]]]\text{False}