Paradox 5.2 | Meta-time 4.2 | Cumulative concept of time, 13.2 | Two dimensional time 4.1 | 二次元時間 4.1
In a “if and only if” case, there is no time.
If A is a necessary condition of B, we say “A is a cause of B“. In other words, A is in the past of B.
However, in some time travel story, it is “possible” to have both
A is a cause of B
(A is a necessary condition of B)
(B -> A)
B is a cause of A
(B is also a necessary condition of A)
(A -> B)
In this case, A and B are just equivalent.
Neither is in the past of another. A and B have no causal relationship. In this sense, there is no time.
— Me@2013-07-03 6:19 PM
2013.07.05 Friday (c) All rights reserved by ACHK