A lithographic projection apparatus including an interferometer system having a reach extending over a first, measurement station and a second, exposure station. The separator and the fuel mixer are separate structures, each including an agitator for stirring a liquid. The printer includes a print carriage which contains only two print cartridges. Interference of light emitted and collected by the fibers creates a 3D fringe pattern. The process includes retaining as an evaluated symbol length the first-symbol length received if the absolute value of the first random phase error reduces a condition of passing through the first state.