Principal Part

The principal part at of a function

is the portion of the Laurent series consisting of terms with negative degree. That is,

is the principal part of at . has an essential singularity at, if and only if the principal part is an infinite sum.

Famous quotes containing the words principal and/or part:

    “The principal office of history I take to be this: to prevent virtuous actions from being forgotten, and that evil words and deeds should fear an infamous reputation with posterity.”
    —Tacitus (c. 55–c. 120)

    “I wonder what subtle form of manslaughter is next on the program. Am I to be dropped into a vat of molten steel and become part of a new skyscraper, or are you going to ask this female to kiss me again and poison me to death?”
    —Ernest Lehman (b.1920)