FILELEX -- "File checker lexfile". Adds FILE? to BASIC.

Size: 64 bytes.

FILE? checks whether or not its argument is a filename that exists in
the HP-71's file chain, even if IRAM, ROM, etc.  If it is, FILE?
returns a 1; if not, it returns a 0.  Most useful in test structures
such as IF NOT FILE?(A$) THEN COPY A$&":TAPE" which loads a file from
disc only if it isn't already in memory.

*** FILELEX ***
(31898) File Header
(318F2) 71/07 FILE?($)
(3193D) Next File Header