+ | SYMBOL "\\HVBOX"; DELIM "\\["; p = l1_pattern; DELIM "\\]" ->
+ return_term loc (Layout (Box (HV, p)))
+ | SYMBOL "\\HOVBOX"; DELIM "\\["; p = l1_pattern; DELIM "\\]" ->
+ return_term loc (Layout (Box (HOV, p)))
+(* | SYMBOL "\\BREAK" -> return_term loc (Layout Break) *)