imperial units are not metric units
metric_linear_unit is not linear_unit. mil is not linear_unit. metric_unit is unit_of_measurement. metric_unit is not unit_of_measurement. british_imperial_system is system_of_weights_and_measures. metric_linear_unit is not metric_unit. imperial is not automobile. metric_unit_of_measure is not metric_system. british_imperial_system is not system_of_weights_and_measures. universal_unit_of_measure is not metric_system.