Given a property , if 
 as 
 (so, using asymptotic notation, the number of numbers less than 
 not satisfying the property 
 is 
, where 
 is one of the so-called Landau symbols), then 
 is said to hold true for almost all numbers. For example, almost all positive integers are composite numbers (which is not in conflict with the second of Euclid's theorems that there are an infinite number of primes). 
Almost All
See also
Almost Surely, Asymptotic Notation, For All, Landau Symbols, Normal OrderExplore with Wolfram|Alpha
References
Hardy, G. H. Ramanujan: Twelve Lectures on Subjects Suggested by His Life and Work, 3rd ed. New York: Chelsea, p. 50, 1999.Hardy, G. H. and Wright, E. M. An Introduction to the Theory of Numbers, 5th ed. Oxford, England: Clarendon Press, p. 8, 1979.Referenced on Wolfram|Alpha
Almost AllCite this as:
Weisstein, Eric W. "Almost All." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/AlmostAll.html