Mechanics in space and counterspace

The completely dual approach to Clifford algebra is used to enlarge the concept of the projective split and to develop a new geometric representation for the Pauli algebra (space and counterspace), for the momenta (planelike vectors), and for the phase space. The Pauli algebra appears in this context as the phase space extended by time (scalar) and energy (pseudoscalar). Lagrangian and Hamiltonian mechanics are embedded into the dual framework of space and counterspace. Several examples illustrate the new techniques. The dual approach to mechanics provides a new possibility to interpret symplectic geometry.