From: Mohammad Abdul Aziz <mohammad.abdulaziz8@gmail.com>
Hello All,
I would like to know whether the integration by substitution identity was
proven for the gauge integral (or some special cases) in the multivariate
analysis library.
Best,
Mohammad
From: Johannes Hölzl <hoelzl@in.tum.de>
Hi Mohammad,
it is not directly available for the Gauge integral in Isabelle/HOL.
Luckily, in HOL-Probability is integration by substitution proved for
continuous f, g :: real => real with "interval_integral_substitution"
or "integral_substitution".
(LBINT x=g a..g b. f x) = (LBINT x=a..b. f (g x) * g' x)
as f and g are continuous the Lebesgue integral and the gauge integral
are equal. This can be proved with "integral_lborel" and
"integrable_on_lborel".
Last updated: Nov 21 2024 at 12:39 UTC