Experimental tests of quantum electrodynamics through the measurement of the reactions e/sup +/e/sup -/. -->. e/sup +/e/sup -/, e/sup +/e/sup -/. -->. gamma gamma. , and e/sup +/e/sup -/. -->. mu. /sup +/. mu. /sup -/ at a center-of-mass energy of 5. 2 GeV

We report measurements of the reactions e/sup +/e/sup -/ ..-->.. e/sup +/e/sup -/, e/sup +/e/sup -/ ..-->.. ..gamma gamma.., and e/sup +/e/sup -/ ..-->.. ..mu../sup +/..mu../sup -/ at angles close to 90/sup 0/, relative to Bhabha scattering, at a center-of-mass energy of 5.2 GeV. The results are found to be in agreement with the predictions of quantum electrodynamics.