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)
“Being in a family is like being in a play. Each birth order position is like a different part in a play, with distinct and separate characteristics for each part. Therefore, if one sibling has already filled a part, such as the good child, other siblings may feel they have to find other parts to play, such as rebellious child, academic child, athletic child, social child, and so on.”
—Jane Nelson (20th century)