  The elements of the theory of vacuum oscillations and the model of dynamical
expansion of the theory of weak interactions works at the tree level, i.e. the
model of dynamical analogy of Cabibbo-Kobayashi- Maskawa matrices and its
further development, are given. It is shown that the quarks and massive vector
bosons must be structural and these structural particles (subparticles) must
interact to generate quark and vector boson masses. In this case the problem of
singularity cancellations does not arise in this model. It is also shown that,
for self consistency of the theory, the weak decays of $K$ mesons must go
through massive vector boson $B$ but not $W$ boson. In the framework of this
model the probability of $\pi \leftrightarrow K$ transitions (oscillations) in
the diagram approach is computed. These transitions are virtual since masses of
$\pi$ and $K$ mesons differ considerably. These transitions (oscillations) can
be registered through $K$ decays after transitions of virtual $K$ mesons to
their own mass shell by using their quasielastic strong interactions.
