Suppose E is true. If D was true, then it would be contradictory. Thus, D would be false, so there are two consecutive true statements. This implies B must be true, and C also is true... but that makes E false. Conclusion: E is false.
Suppose D is also false; this makes A false. Since there are two consecutive true statements, B and C must be true... but this makes E true. Conclusion: D is true.
Since D is true, C must be false, and that implies A and B must also be false.
Edited on October 12, 2004, 6:39 pm