It's B. BCPL has "LET MAIN() BE $(..." instead of "main $(...".
Running B was a challenge on the PDP-7 but easier on the PDP-11, apparently, because of the increase of memory size. The linked document has an interesting history about compiling B to threaded code, a form of interpreted code, and then to machine language. B never really made the jump to a full-fledged citizen because it quickly got replaced by C, although BCPL was popular for a long time.
Running B was a challenge on the PDP-7 but easier on the PDP-11, apparently, because of the increase of memory size. The linked document has an interesting history about compiling B to threaded code, a form of interpreted code, and then to machine language. B never really made the jump to a full-fledged citizen because it quickly got replaced by C, although BCPL was popular for a long time.
https://www.bell-labs.com/usr/dmr/www/chist.html