1 Regexp: ((a|b|c)def) 2 adef: Ok 3 bdef: Ok 4 adefg: Fail 5 aaef: Fail 6 Regexp: ((a|b|c|d|e|f)?(g|h|i)+(k|l)*) 7 g: Ok 8 gi: Ok 9 fil: Ok 10 gikl: Ok 11 cghhhiill: Ok 12 ak: Fail 13