The syntax is the same as the syntax for .((o)), but encoded as a directory structure. I recommend you simply try it out using
gplz.py fibonacci.easy fibonacci./
It will create a subdirectory "fibonacci" with the proper directory structure for you. Then, you can call the programm using
Unfortunately, it is not feasible to display a directory structure in a .htm document. This makes ./ one of the most difficult to spread languages in existence. ./ is therefore extremely safe! Here is a batchfile that will create the directory structure that can be used to calculate the first 20 fibonacci numbers:
mkdir nix\0\(\(\f\(\x\)\=\(\(\i mkdir nix\1\=\x\)\,\(\j\=\x\)\, mkdir nix\2\(\c\=\(\x\-\x\)\)\) mkdir nix\3\,\(\(\f\(\1\)\)\,\( mkdir nix\4\W\H\I\L\E\_\(\c\'\2 mkdir nix\5\0\)\_\D\O\_\(\(\'\' mkdir nix\6\j\)\,\(\h\=\(\j\+\i mkdir nix\7\)\)\,\(\j\=\i\)\,\( mkdir nix\8\i\=\h\)\,\(\c\+\=\1 mkdir nix\9\)\)
You should understand that this is not a ./ program, its a batchfile that creates a ./ program.