Am So., 13. Sept. 2020 um 14:57 Uhr schrieb Felix Thibault
<xxxxxx@gmail.com>:

> This is one area of Scheme I am still learning about. If the expression is ``,x I get matches from the patterns

The expression ``,x evaluates to the datum (quasiquote (unquote x)).

> (quote (quasi-quote (unquote x))) ['`,x] and

This pattern asks for a literal match to (quasiquote (unquote x)), so
it succeeds.

> (quasi-quote (unquote (quasi-quote (unquote x)))) [`,`,x]

If the quasiquote syntax of the pattern matcher works as the
quasiquote special for of the RnRS (which isn't yet documented in SRFI
204), (quasiquote (unquote ...)) is equivalent to .... So your pattern
is equivalent to the pattern variable (!) x, which, of course, matches
the datum (quasiquote (unquote x)).

Does this explanation help? (And were you actually looking for it?)

Marc