Fermilab-Tevatron. Measurement of the electron charge asymmetry in inclusive W production in PBAR P interactions at a centre of mass energy of 1.96 TeV. The data sample has a total integrated luminosity of 0.75 pb-1.. The asymmetry ASYM is defined as:. (DSIG(E+)/DETARAP-DSIG(E-)/DETARAP)/(DSIG(E+)/DETARAP+DSIG(E-)/DETARAP).