English
If t is continuous and f is continuous, then the map x ↦ ϕ (t x) (f x) is continuous.
Русский
Если t непрерывна и f непрерывна, то отображение x ↦ ϕ(t(x))(f(x)) непрерывно.
LaTeX
$$$\text{Continuous } t \Rightarrow \text{Continuous } f \Rightarrow \text{Continuous }(x \mapsto \varphi(t(x))(f(x))).$$$
Lean4
/-- The orbit of a point under a flow. -/
def orbit (x : α) : Set α :=
ϕ.toAddAction.orbit _ x