Parameters	Short description
t	given time
$\vec{r}$	position of the starting point of a ballistic trajectory of the diverging particle
${\vec{r}}^{'}$	position of the ending point of a ballistic trajectory of the diverging particle
${t^{'}}_{a}$	time of positioning the ending point of the diverging particle
$n (t, \vec{r})$	particle density in the starting point $\vec{r}$ at the given time t
$\vec{u} (\vec{r}, t)$	mass flow velocity in point $\vec{r}$ at time t
$v_{T} (\vec{r}, t)$	the average magnitude of the thermal velocity of a diverging particle in point $\vec{r}$ at time t
${\vec{v}}_{+} (t, \vec{r}, {t^{'}}_{a})$	the velocity vector of the diverging particle at the time of positioning in point ${\vec{r}}^{'}$
${\vec{r}}_{a}^{c} (t, \vec{r}, \tilde{t})$	the position of a virtual ballistic particle at time $\tilde{t}$ , which has zero magnitude of thermal velocity in the starting point $\vec{r}$ at the time of initial collision t
${\vec{v}}_{a}^{c} (t, \vec{r}, \tilde{t})$	the velocity vector of the virtual ballistic particle at time $\tilde{t}$
$Q_{+} ({t^{'}}_{a}, t)$	the probability of free path traveling along the ballistic trajectory starting at time t and ending at time ${t^{'}}_{a}$
$Ψ (t, \vec{r}, {t^{'}}_{a}, {\vec{r}}^{'})$	property content carried by the diverging particle at the time ${t^{'}}_{a}$ of crossing in point ${\vec{r}}^{'}$ enclosing control surface 503