A very special island is inhabited only by knights and knaves. Knights always tell the truth, and knaves always lie. You meet 6 inhabitants: Penelope, Liam, Sebastian, Victoria, Jackson, and Aria. Penelope remarked, "Sebastian is a knight or Victoria is a knave". Liam expressed that Sebastian is a knight or Aria is a knight. Sebastian commented, "Aria is a knave if and only if Liam is a knave". Victoria noted, "If Penelope is a knight then Aria is a knave". Jackson said that Jackson is a knight or Victoria is a knight. Aria remarked, "Sebastian is a knave or Jackson is a knave". So who is a knight and who is a knave?
Penelope is a knight, Liam is a knight, Sebastian is a knight, Victoria is a knave, Jackson is a knave, and Aria is a knight.
(1) Penelope is a knight
(2) Liam is a knight
(3) Sebastian is a knight
(4) Victoria is a knave
(5) Jackson is a knave
(6) Aria is a knight
Assume Penelope is a knight. No contradiction is found in their claim that Sebastian is a knight or Victoria is a knave. Assume Sebastian is a knight. No contradiction is found in their claim that Aria is a knave if and only if Liam is a knave. Assume Aria is a knight. No contradiction is found in their claim that Sebastian is a knave or Jackson is a knave. Jackson cannot be a knight, because this would contradict the claim of Aria that Sebastian is a knave or Jackson is a knave. Assume Jackson is a knave. No contradiction is found in their false claim that Jackson is a knight or Victoria is a knight. Victoria cannot be a knight, because this would contradict the claim of their own that If Penelope is a knight then Aria is a knave. Assume Victoria is a knave. No contradiction is found in their false claim that If Penelope is a knight then Aria is a knave. Assume Liam is a knight. No contradiction is found in their claim that Sebastian is a knight or Aria is a knight.