Parse escape sequences in strings

doc/appendix.tex

@@ -17,7 +17,7 @@
 <hex-character> = `\\x' <hex-digit> \{<hex-digit>\}.
 
 <escaped-character> = `\\' \\
-	(`n' | `a' | `b' | `t' | `f' | `r' | `v' | `\\' | `\textquotesingle' | `\textquotedbl' | `0').
+	(`n' | `t' | `f' | `r' | `v' | `\\' | `\textquotesingle' | `\textquotedbl' | `0').
 
 <printable-character> = \enspace? a printable ASCII character\space?.
 

doc/language.tex

@@ -84,7 +84,7 @@ called the \textit{the length} of the string.
 
 \begin{grammar}
 <escaped-character> = `\\' \\
-	(`n' | `a' | `b' | `t' | `f' | `r' | `v' | `\\' | `\textquotesingle' | `\textquotedbl' | `0').
+	(`n' | `t' | `f' | `r' | `v' | `\\' | `\textquotesingle' | `\textquotedbl' | `0').
 
 <hex-character> = `\\x' <hex-digit> \{<hex-digit>\}.
 
@@ -106,10 +106,6 @@ beginning with a backslash (\textbackslash).
 	\toprule
 	\verb|\n| & Newline \\
 	\midrule
-	\verb|\a| & Bell \\
-	\midrule
-	\verb|\b| & Backspace \\
-	\midrule
 	\verb|\t| & Horizontal tab \\
 	\midrule
 	\verb|\f| & Form feed \\