Exactly, "a fleck on the speck on the tail on the frog on the bump on the branch on the log in the hole in the bottom of the sea" only has stack depth 1 as long

Exactly, "a fleck on the speck on the tail on the frog on the bump on the branch on the log in the hole in the bottom of the sea" only has stack depth 1 as long as you can do a kind of tail call optimization (aka left-corner parsing with an arc-eager transition, see https://www.aclweb.org/anthology/C92-1032.pdf https://www.aclweb.org/anthology/C92-1032.pdf)