+//usage:#define comm_trivial_usage
+//usage: "[-123] FILE1 FILE2"
+//usage:#define comm_full_usage "\n\n"
+//usage: "Compare FILE1 with FILE2\n"
+//usage: "\n -1 Suppress lines unique to FILE1"
+//usage: "\n -2 Suppress lines unique to FILE2"
+//usage: "\n -3 Suppress lines common to both files"
+