 This equation is interpreted as connecting spin with the imaginary pseudoscalar.formula_60 is viewed as a Lorentz rotation which a frame of vectors formula_61 into another frame of vectors formula_62 by the operation formula_63, where the tilde symbol indicates the "reverse" (the reverse is often also denoted by the dagger symbol, see also Rotations in geometric algebra).This has been extended to provide a framework for locally varying vector- and scalar-valued observables and support for the Zitterbewegung interpretation of quantum mechanics originally proposed by Schrödinger.