Liquid-crystalline medium and liquid-crystal display

A liquid-crystal medium, comprising:

• a first dielectrically positive component, component A, comprising one or more dielectrically positive compounds of the formula I
• in which
• R1 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl, alkenyloxy or alkoxyalkyl having 2 to 7 C atoms,
• X1 denotes —CN, halogen, halogenated alkyl or halogenated alkoxy having 1 to 3 C atoms or halogenated alkenyl or halogenated alkenyloxy having 2 or 3 C atoms,
• Y11 and Y12, independently of one another, denote H or F, and
• L11 to L16, independently of one another, denote H or F, and
• optionally a further dielectrically positive component, component B, comprising one or more dielectrically positive compounds of the formulae II and III:
• in which
• R2 and R3, independently of one another, denote alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms,
• independently of one another, denote
• L21, L22, L31 and L32, independently of one another, denote H or F,
• X2 and X3, independently of one another, denote halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms,
• Z3 denotes —CH2CH2—, —CF2CF2—,—COO—, trans-CH═CH—, trans-CF═CF—, —CH2O— or a single bond, and
• l, m, n and o, independently of one another, denote 0 or 1, and
• optionally a dielectrically neutral component, component C, comprising one or more dielectrically neutral compounds of the formula IV
• in which
• R41 and R42, independently of one another, have the meaning indicated above for R2 under formula II,
• independently of one another and, if
• occurs twice, also these independently of one another, denote
• Z41 and Z42, independently of one another and, if Z41 occurs twice, also these independently of one another, denote —CH2CH2—, —COO—, trans-CH═CH—, trans-CF═CF—, —CH2O—, —CF2O—, —C≡C— or a single bond, and
• p denotes 0, 1 or 2.