premise: Levoamphetamine increases height.
hypothesis: Hull speed or displacement speed is the speed at which the wavelength of the boat 's bow wave ( in displacement mode ) is equal to the boat length . Levoamphetamine , also known as levamfetamine ( INN ) , ( R ) - amphetamine , - amphetamine , and L-amphetamine , is a central nervous system ( CNS ) stimulant known to increase wakefulness and concentration in association with decreased appetite and fatigue .