  An extensive program for the calculation of galactic cosmic-ray propagation
has been developed. Primary and secondary nucleons, primary and secondary
electrons, and secondary positrons are included. The basic spatial propagation
mechanisms are (momentum-dependent) diffusion, convection, while in momentum
space energy loss and diffusive reacceleration are treated. Fragmentation and
energy losses are computed using realistic distributions for the interstellar
gas and radiation fields. Predictions of the diffuse Galactic gamma ray and
synchrotron emission are made. Our new estimate of the cosmic-ray positron
spectrum is compared with the latest experimental data.
