backslashedp
VBARREDP char
VBARRED? char
BACKSLASHED? char (library procedure)
outputs TRUE if the input character was originally entered into Logo
within vertical bars (|) to prevent its usual special syntactic
meaning, FALSE otherwise. (Outputs TRUE only if the character is a
backslashed space, tab, newline, or one of ()[]+-*/=<>":;\~?| )
The names BACKSLASHEDP and BACKSLASHED? are included in the Logo
library for backward compatibility with the former names of this
primitive, although it does *not* output TRUE for characters
originally entered with backslashes.