Writing the coordinates in column vectors and the Minkowski metric η as a square matrix X ′ = [ c t ′ x ′ y ′ z ′ ] , η η = [ − − 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 ] , X = [ c t x y z ] the spacetime interval takes the form (superscript T denotes transpose) X ⋅ ⋅ X = X T η η X = X ′ T η η X ′ and is invariant under a Lorentz transformation X ′ = Λ Λ X where Λ is a square matrix which can depend on parameters.