Hi,
I've been investigating the behaviour of threads created in the same lexical scope, and I have to admit that I'm a little puzzled.
The documentation states, that the "call-with-new-thread" procedure calls its argument in a new thread and with a new dynamic state, the latter being described in more detail with the introduction of the notion of fluids.
Nothing is being said regarding the behaviour of new thread with respect to the current lexical scope.
The test program below shows, that each thread obtains its own copy of a current lexical scope: