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Not operation
 The not operation
 Description: This operation take a single value and negates it.
 Expression: f(x) = x'
 Sometimes written $\lnot x$, x
 I will use either x' (our book) or x (Many other books, but harder to make in html)
 Truth Table
 Building truth tables.
 For a truth table, list all possible permutations of the input
 Then list the output values.
 If there are n variables, there will be $2^n$ output values.
 When building a truth table,
 Write the $n$ input variables across the top.
 Then count from 0 to $2^n$ in binary under these.
 For not there is a single variable, so there are $2^1 = 2$ rows or output values.

 The symbol for a not gate
 A triangle with a circle on the end.

 Talk about drawing this on tests.
Not is sometimes called in inverter
 And we invert the input or output of a gate/circuit.
 The input is inverted, (not notted)
Not from transistors.
 We can implement a not gate from two transistors.
 A positive voltage goes to the emitter of the PNP
 A the emitter of the NPN is hoked to the ground
 The two collectors are hooked together and form the output of the circuit
 The input value (x above) is hooked to both bases.

 The digital file
Not with other gates
 Nots are frequently displayed as just a circle with other gates.
 This is an and gate
 This is an and gate with the first input inverted
 To do this in digital
 Right click on the gate.
 Click on the button associated with Inverted inputs:
 Select the inputs you wish to invert.