Union of Slow g-Tower is Well-Orderable

Theorem
Let $M$ be a class.

Let $g: M \to M$ be a slowly progressing mapping on $M$.

Let $M$ be a slow $g$-tower.

Then $\ds \bigcup M$ is well-orderable.

Proof
Let $M$ be a slow $g$-tower.

From Slow $g$-Tower is Slowly Well-Ordered under Subset Relation we have that $M$ is slowly well-ordered under $\subseteq$.

The result follows from Union of Slowly Well-Ordered Class under Subset Relation is Well-Orderable.