b) (5pt) Build a regular expression that captures all non-empty sequences of letters other than "for". For your convenience, you may use a "not" operator that takes a set of letters as argument and matches any other letter. For instance, not(abc) matches any letter other than a, b and c. Use to match any letter. b) (5pt) Build a regular expression that captures all non-empty sequences of letters other than "for". For your convenience, you may use a "not" operator that takes a set of letters as argument and matches any other letter. For instance, not(abc) matches any letter other than a, b and c. Use to match any letter