14 echo +([[:alpha:].])+([[:alpha:].])
16 echo *([[:alpha:].])*([[:alpha:].])
18 echo ?([[:alpha:].])?([[:alpha:].])?([[:alpha:].])
19 echo @([[:alpha:].])@([[:alpha:].])@([[:alpha:].])
22 !([[:alpha:].]) ) echo bad 1;;
27 ?([[:alpha:].]) ) echo ok 2;;
32 @([[:alpha:].]) ) echo ok 3;;