Glasser's master theorem

In integral calculus, Glasser's master theorem explains how a certain broad class of substitutions can simplify certain integrals over the whole interval from

It is applicable in cases where the integrals must be construed as Cauchy principal values, and a fortiori it is applicable when the integral converges absolutely.

It is named after M. L. Glasser, who introduced it in 1983.

[1] A special case called the Cauchy–Schlömilch substitution or Cauchy–Schlömilch transformation[2] was known to Cauchy in the early 19th century.

[3] It states that if then where PV denotes the Cauchy principal value.