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:

    There are three principal means of acquiring knowledge available to us: observation of nature, reflection, and experimentation. Observation collects facts; reflection combines them; experimentation verifies the result of that combination. Our observation of nature must be diligent, our reflection profound, and our experiments exact. We rarely see these three means combined; and for this reason, creative geniuses are not common.
    Denis Diderot (1713–1784)

    Nothing more powerfully excites any affection than to conceal some part of its object, by throwing it into a kind of shade, which at the same time that it shows enough to prepossess us in favour of the object, leaves still some work for the imagination.
    David Hume (1711–1776)