Henstock–Kurzweil integral
GENERALIZATION OF THE RIEMANN INTEGRAL
Henstock-Kurzweil Integral; Perron integral; Gauge integral; Henstock integral; Denjoy Integral; Henstock-Kurzweil-Stieltjes integral; Perron Integral; Henstock-Kurzweil-Stieltjes Integral; Generalized Riemann integral; Denjoy-Perron integral; Henstock-Kurzweil integral; H-K integral
In mathematics, the Henstock–Kurzweil integral or generalized Riemann integral or gauge integral – also known as the (narrow) Denjoy integral (pronounced ), Luzin integral or Perron integral, but not to be confused with the more general wide Denjoy integral – is one of a number of inequivalent definitions of the integral of a function. It is a generalization of the Riemann integral, and in some situations is more general than the Lebesgue integral.