[stack] Properties of Concatenative langauges and Forth

In a concatenative language, I believe evaluation order should be unimportant.

For example:

f g h <=> (f g) h <=> f (g h)

Does Forth have this property?

Another property that I expect from a concatenative language is that
any subsequence of terms can be replaced with a subroutine whose
definition consists of that subsequence, without changing the meaning
of the program. I believe this follows from the description of Joy
that says that the syntax is a homomorphism to the semantics.

For example:

define sub { a b }
a b c a b <=> sub c sub

Does Forth have this property?

What about Enchilada?

FWIW: I like Steven Apter's informal definition a lot. Concatenative
means Joy-like. I am really worrying so much about definitions because
I am interested in trying to get at the heart of what makes Joy so
darn interesting from a theoretical stand-point, so that I can talk to
academics and say "see, Joy is not like your language!"

- Christopher