  It is shown with the help of skew-symmetric forms that the mathematical
physics equations, on which no additional conditions are imposed, have quantum
properties. And this is due to the integrability properties of differential
equations, which depends on the consistency of derivatives with respect to
different variables and the consistency of equations, if the mathematical
physics equations are a system of equations. It was found that such equations
on the original tangent space turn out to be non-integrable. Their derivatives
do not form a differential. The integrability of such equations is realized
only on the structures of a cotangent integrable manifold. This happens using a
degenerate, non-differential-preserving transformation that has quantum
properties. When implementing degenerate transformations, mini structures
(quanta) arise, from which integrable structures are formed. Such properties of
integrability of mathematical physics equations and features of degenerate
transformations reveal the quantum properties of mathematical physics equations
and their ability to generate quantum structures.
