:= |

:= "IF" "THEN" "ELSE" |

:= "IF" "THEN" | "IF" "THEN" "ELSE" ##

##

sub stmt
{
   my $buf = shift;

   if (matched_stmt($buf)) {
      return 1;
   }
   elsif (unmatched_stmt($buf)) {
      return 1;
   }
   return 0;
}

# etc.