1BEGIN {
2	range = "[a-dx-z]"
3
4	split("ABCDEFGHIJKLMNOPQRSTUVWXYZ", upper, "")
5	split("abcdefghijklmnopqrstuvwxyz", lower, "")
6
7	for (i = 1; i in upper; i++)
8		printf("%s ~ %s ---> %s\n",
9			upper[i], range, (upper[i] ~ range) ? "true" : "false")
10
11	for (i = 1; i in lower; i++)
12		printf("%s ~ %s ---> %s\n",
13			lower[i], range, (lower[i] ~ range) ? "true" : "false")
14}
15