  A search for B0s oscillations is performed using a sample of semileptonic
b-hadron decays collected by the ALEPH experiment during 1991-1995. Compared to
previous inclusive lepton analyses, the proper time resolution and b-flavour
mistag rate are significantly improved. Additional sensitivity to B0s mixing is
obtained by identifying subsamples of events having a B0s purity which is
higher than the average for the whole data sample. Unbinned maximum likelihood
amplitude fits are performed to derive a lower limit of Deltam_s>9.5ps^-1 at
95% CL. Combining with the ALEPH D-s based analyses yields Deltam_s>9.6ps^-1 at
95% CL.
