a-z, 0-9, space literal match[], (), {} character classes & groups|, ., ?, *, + alternation & repetition"expr" exact phrase (no spaces)expr & expr intersection (conjunction)<anagram> anagram of letters_ alphanumeric [a-z0-9]# digit [0-9]- optional space ( ?)A, C, V letter, consonant, vowelinspired by nutrimatic