Let 
be an information source with entropy 
. Then
 |
where 
is the minimum average code-word length among all uniquely decipherable coding schemes
for 
Shannon's Noiseless Coding Theorem
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References
Casti, J. L. "The Shannon Coding Theorem." Ch. 1 in Five More Golden Rules: Knots, Codes, Chaos, and Other Great Theories of 20th-Century Mathematics. New York: Wiley, pp. 207-254, 2000.Referenced on Wolfram|Alpha
Shannon's Noiseless Coding TheoremCite this as:
Weisstein, Eric W. "Shannon's Noiseless Coding Theorem." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/ShannonsNoiselessCodingTheorem.html