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:
“This place is the Devil, or at least his principal residence, they call it the University, but any other appellation would have suited it much better, for study is the last pursuit of the society; the Master eats, drinks, and sleeps, the Fellows drink, dispute and pun, the employments of the undergraduates you will probably conjecture without my description.”
—George Gordon Noel Byron (1788–1824)
“As she laughed I was aware of becoming involved in her laughter
and being part of it, until her teeth were only accidental stars with
a talent for squad-drill.”
—T.S. (Thomas Stearns)