[gambit-list] The module system

Hi,

I'm reading in "A tour of Scheme in Gambit" about the "X Module System", on page 40:

http://dynamo.iro.umontreal.ca/~gambit/wiki/images/a/a7/A_Tour_of_Scheme_in_...

It mentions two forms: "module" and "use", and describes how a module will be recompiled if the module source is newer than the binary. This sounds great, but in gsi, or when I compile a file with gsc, neither "module" nor "use" are available:

gambit # gsi Gambit v4.6.1

...

module

*** ERROR IN (console)@1.1 -- Unbound variable: module 1> (module a_module) *** ERROR IN (console)@2.2 -- Unbound variable: module 2>

Is this something that has been removed, or do I have to turn it on?

Thank you, Benjohn