-/*-------------------------------------------------------------------.
-| Set FIRSTS to be an NVARS by NVARS bit matrix indicating which |
-| items can represent the beginning of the input corresponding to |
-| which other items. |
-| |
-| For example, if some rule expands symbol 5 into the sequence of |
-| symbols 8 3 20, the symbol 8 can be the beginning of the data for |
-| symbol 5, so the bit [8 - ntokens, 5 - ntokens] in firsts is set. |
-`-------------------------------------------------------------------*/
+/*------------------------------------------------------------------.
+| Set FIRSTS to be an NVARS array of NVARS bitsets indicating which |
+| items can represent the beginning of the input corresponding to |
+| which other items. |
+| |
+| For example, if some rule expands symbol 5 into the sequence of |
+| symbols 8 3 20, the symbol 8 can be the beginning of the data for |
+| symbol 5, so the bit [8 - ntokens] in first[5 - ntokens] (= FIRST |
+| (5)) is set. |
+`------------------------------------------------------------------*/