(cont.)
(br)      --   Branches by the number specified in the 2
               following bytes. Can be negative.
(?br)     f -- Branch if f is false.
(         --   *I* Comment. Ignore input until ")" is read.
[         --   Begin interpretative mode. In a definition,
               execute words instead of compiling them.
]         --   End interpretative mode.
ABORT     --   Resets PS and RS and returns to interpreter.
ABORT" x" --   *I* Compiles a ." followed by a ABORT.
EXECUTE   a -- Execute wordref at addr a
INTERPRET --   Get a line from stdin, compile it in tmp memory,
               then execute the compiled contents.
LEAVE     --   In a DO..LOOP, exit at the next LOOP call.
QUIT      --   Return to interpreter prompt immediately
EXIT!     --   Exit current INTERPRET loop.