What is it that you want that code to do? I'm not sure I see why that's a bug. You seem to be providing two arguments, 0 and 1, to a function that only expects one, '_ .
The OP is presuming that anarki hacked the bracketed functions to accept multiple arguments. I remember reading that somewhere as well, but since I haven't tried using the feature before I don't really know.
Thanks, it seems like my brain was scrambled last night. _0 and _1 (or _a and _b) are the appropriate pieces of code. But the real problem was that I was operating out of an arc directing that was lacking a load/ directory. Thus I was missing the make-br-fn.arc file. Fixed now. Thanks guys!