Editing Fractional calculus (section)

=== Nature of the fractional derivative ===
The {{nowrap|<math>a</math>-th}} derivative of a function <math>f</math> at a point <math>x</math> is a ''local property'' only when <math>a</math> is an integer; this is not the case for non-integer power derivatives. In other words, a non-integer fractional derivative of <math>f</math> at <math>x=c</math> depends on all values of {{nowrap|<math>f</math>,}} even those far away from {{nowrap|<math>c</math>.}} Therefore, it is expected that the fractional derivative operation involves some sort of [[boundary condition]]s, involving information on the function further out.<ref>{{MathPages|id=home/kmath616/kmath616.htm|title=Fractional Calculus}}</ref>

The fractional derivative of a function of order <math>a</math> is nowadays often defined by means of the [[Fourier transform|Fourier]] or [[Mellin transform|Mellin]] integral transforms.{{Citation needed|date=November 2022|reason=Examination of recent papers does not mention this}}