Definition:Principal


 * Logic
 * Definition:Principal Operator


 * Order Theory
 * Definition:Principal Ideal of Ordered Set


 * Matrix Algebra
 * Definition:Principal Diagonal


 * Real Analysis:
 * Definition:Principal Square Root


 * Complex Analysis:
 * Definition:Principal Branch
 * Definition:Principal Range
 * Definition:Principal Argument


 * Number Theory
 * Definition:Principal Remainder


 * Analytic Number Theory
 * Definition:Principal Character


 * Ideal Theory
 * Definition:Principal Ideal of Ring
 * Definition:Principal Ideal Domain


 * Filter Theory
 * Definition:Principal Ultrafilter