Hi Fred.
Your example:
"On the other hand, take this as an example:
at time t0) [A is preferred to B] and [B is preferred to C]."
I think what Mises is trying to say, and what you may be missing, is that in his conception of preference, there are only 2 “categories” so to speak: that which is chosen (preferred), and that which is set aside.
Your example shows two instances of preferring by Mises’s conception (i.e., two sets of two categories). So by Mises’s conception, those are two separate acts.
I’m not sure whether you’re seeing Mises’s meaning.
I think you can see it more clearly if you extend the series you are using as an example:
at time t0) A is preferred to B, and B is preferred to C, and C is preferred to D, and D is preferred to E, and E is preferred to F, and F is preferred to G, and G is preferred to H…
Then, is this a formal-logical construct, or a description of action in the temporal order?
Mises is saying that if it is a formal construct, it is “a-temporal.” If it is a description of action, each listed preference is a separate act of preference:
act 1: preferring A to B
act 2: preferring B to C
act 3: preferring C to D
etc…
I think if you read Mises’s passage with this in mind, you may better catch his meaning.