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:
“With a balanced combination of the two principal energies from mother and father, a girl can both be in touch with her womanly strengths and be a powerful force in the world—strong and nurturing, decisive and caring, goal- oriented and aware of the needs of others. She has the courage to voice what she thinks and feels and the strength to follow her destiny.”
—Jeanne Elium (20th century)
“Frequently also some fair-weather finery ripped off a vessel by a storm near the coast was nailed up against an outhouse. I saw fastened to a shed near the lighthouse a long new sign with the words “ANGLO SAXON” on it in large gilt letters, as if it were a useless part which the ship could afford to lose, or which the sailors had discharged at the same time with the pilot. But it interested somewhat as if it had been a part of the Argo, clipped off in passing through the Symplegades.”
—Henry David Thoreau (1817–1862)