A small white notes (don't know is what, with reference to the pirated books)
The first layer:
Physical theorem on the natural attribute of abstract (abstraction is the process of discretization of particles)

The second:
Set the total separation of the original abstract (power supply, resistance, capacitance)

The third layer:
6.002 amplifier (op amp) abstract

The fourth floor:
Line Numbers abstract (reverse phase door, composite door)

Layer 5:
Combination function abstraction (input, function, output)

Sixth:
Digital clock (abstract definition for each function module sequence)

Layer 7:
Machine code abstract the microinstruction (register) (information interchange code)

8 layers:
Assembly instruction abstract (extraction, decode, execute, write back)

Ninth:
Language abstractions (constants, variables)

The first ten layers:
The kernel interface abstraction (global control)

The eleventh floor:
Application interface abstraction (function)