x_{1} is the linear-momentum-energy-mass [four-vector] of x_{2} in frame of reference x_{3}

Be careful to define the order and units of the four vector. See also: nejni, impetu, ocnerta, tcelerita.

- impetu
- x
_{1}is the momentum [vector] of x_{2}in frame of reference x_{3} - ocnerta
- x
_{1}is a physically-required conserved quantity in an ideal closed system such that it is associated with (Noetherian) symmetry/Hamiltonian-commuting observable/deterministic feature/law/property/aspect x_{2}, applicable under conditions/in universe/in metaphysics x_{3} - sirmpetu
- x
_{1}is the [probably spatial] linear momentum [vector] of x_{2}in frame of reference x_{3}