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:
“Today, only a fool would offer herself as the singular role model for the Good Mother. Most of us know not to tempt the fates. The moment I felt sure I had everything under control would invariably be the moment right before the principal called to report that one of my sons had just driven somebody’s motorcycle through the high school gymnasium.”
—Mary Kay Blakely (20th century)
“An ordinary man will work every day for a year at shoveling dirt to support his body, or a family of bodies; but he is an extraordinary man who will work a whole day in a year for the support of his soul. Even the priests, men of God, so called, for the most part confess that they work for the support of the body.”
—Henry David Thoreau (1817–1862)