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:
“I cannot believe that our factory system is the best mode by which men may get clothing. The condition of the operatives is becoming every day more like that of the English; and it cannot be wondered at, since, as far as I have heard or observed, the principal object is, not that mankind may be well and honestly clad, but, unquestionably, that the corporations may be enriched.”
—Henry David Thoreau (1817–1862)
“Thus when I come to shape here at this table between my hands the story of my life and set it before you as a complete thing, I have to recall things gone far, gone deep, sunk into this life or that and become part of it; dreams, too, things surrounding me, and the inmates, those old half-articulate ghosts who keep up their hauntings by day and night ... shadows of people one might have been; unborn selves.”
—Virginia Woolf (1882–1941)