大O符号
is formula_55 As seen by this example, the asymptotics of the function as formula_56 define the left endpoint of its fundamental strip, and the asymptotics of the function as formula_57 define its right endpoint. To summarize using Big O notation, if formula_43 is formula_59 as formula_56 and formula_61 as formula_62 then formula_52 is defined in the strip formula_55