Graph Theory – Does $ TREE (x) = {SSCG (x-1) | SSCG (x) } $?

In Graph Minors by Adam P. Goucher, it is shown that:

SSCG (2) «TREE (3)« SSCG (3), where «indicates« incredibly superior to »

As a non-standard surrealist, this could be represented as:

$$ TREE (3) = {SSCG (2) | SSCG (3) } $$

Is this valid for an arbitrary? $ x $ such that

$$ TREE (x) = {SSCG (x-1) | SSCG (x) } $$