RB211-524 manual says:
C. The engine is a high by-pass ratio, three-shaft turbofan consisting,
basically, of a gas generator system and a mechanically independent L.P.
system.
D. The gas generator system comprises a seven-stage intermediate pressure
(I.P.) compressor, a six-stage high pressure (H.P.) compressor, an
annular combustion section and single-stage I.P. and H.P. turbines.
E. The L.P. system consists of a single-stage compressor (fan) driven by a
three-stage turbine.
The CF6-50 engine is a dual-rotor, axial-flow, gas turbine turbofan.
Basic design is based on a high compression, high bypass ratio concept.
B. An integrated, 4-stage, front fan and low pressure compressor is
driven by a 4-stage low pressure turbine which combines to form the N1
rotor.
The 14-stage high pressure compressor is driven by a 2-stage
high pressure turbine which combines to form the N2 rotor. Each rotor
is mechanically independent of the other.