Generalized Tricomi and Hermite–Tricomi functions

General classes of Tricomi and Hermite–Tricomi functions are introduced by exploiting properties of an iterated isomorphism, related to the so-called Laguerre-type exponentials, and we mainly consider the properties of the general classes of 3-variable 2-index Tricomi functions and 2-index 4-variable 1-parameter Hermite–Tricomi functions.