Find the Spy Among Six
Six people, Ada, Bram, Cora, Dev, Eve and Finn, include exactly one spy (who may say anything, true or false); each of the other five is a knight (always truthful) or a knave (always lying). Treat "spy" as a third type when comparing types. They say: - Ada: "Bram is a knight." - Bram: "Ada is a knave." - Cora: "Finn and Dev are of the same type." - Dev: "Bram and Cora are of the same type." - Eve: "Ada is not the spy." - Finn: "Bram is not the spy." Who is the spy? Answer with the name.
Related problems & prerequisites
Worth solving first
Source: Original puzzle; the 'spy' who may say anything is a standard extension of Smullyan's knights and knaves. Statement written for AxiomIQ.