Equation Icon  ∂tf + ˆv ⋅ ∇xf + (E (t,x) + vˆ× B (t,x)) ⋅ ∇vf = 0 (12 ) ∂tE + j = c∇ × B, ∇ ⋅ E = ρ, (13 ) ∂tB = − c∇ × E, ∇ ⋅ B = 0. (14 )