Questions about Conceptual Model of Rule Versioning and Metarules - #1

[Tara Athan <taraathan@gmail.com>]

I have a number of questions regarding the conceptual model behind rule 
versions and metarules. I am going to try to break these up into 
separate parts. Here's the first:

I can think of (at least) two different ways to conceptualize the 
temporal nature of a metarule that introduces (only) a syntactic change 
in the legal text. I want to assume that this syntactic change 
corresponds to an unambiguous semantic change, so that we don't get into 
such complications at this point. The syntactic change might have 
multiple parts (insertions, deletions, replacements), but let's treat it 
as a unit which unambiguously takes the existing text (v1) to some new 
text (v2). Further, let's suppose, again for simplicity, that there is 
no unambiguity in the syntax, so there is precisely one "rule" for each 
text as opposed to multiple interpretations.

Simple example. Let's suppose we have
a) the original version of the rule (#rule-v1), and for simplicity 
suppose that all three start times are identical (#t1 = start of 
efficacy = start of applicability = start of enforcability of #rule-v1)
b) a metarule (#mrule) describing the syntactic change, with time (#t1 < 
#t2 = start of efficacy = start of applicability = start of 
enforcability of #mrule)

Option1.  #t2 = end of efficacy = end of applicability = end of 
enforcability of #rule-v1.
A new "virtual" rule #rule-v2 comes into being, with #t2 = start of 
efficacy = start of applicability = start of enforcability of #rule-v2. 
The temporal effect of #mrule is instantaneous; that is, once it has 
brought #rule-v2 into being, its effect is finished. That is, #t2 = end 
of efficacy = end of applicability = end of enforcability of #mrule. The 
time at which efficacy, etc of #rule-v2 ends is independent of the 
temporal characteristics of #mrule. Also, #t2 = end of efficacy = end of 
applicability = end of enforcability of #rule-v1.

Option 2. #rule-v1 continues to be in effect, etc after #t2, in 
combination with #mrule. The combined effect of #rule-v1 + #mrule is 
logically equivalent to #rule-v2, but #rule-v2 doesn't have independent 
temporal characteristics. The time at which efficacy, etc of #rule-v2 
ends is dependent on the temporal characteristics of #mrule. So there 
may be a #t3 = end of efficacy = end of applicability = end of 
enforcability of #mrule (brought about, say by an explicit rescinding of 
#mrule) and further, #t3 = end of efficacy = end of applicability = end 
of enforcability of #rule-v2. If #rule-v1 is rescinded, then this also 
brings an end to #rule-v2.

So here's my (multi-part) question:
a) Is there one right choice between the conceptual models described in 
Options 1 & 2 (or some other option)? (If so, which one?)
b) If the answer to (a) is no, can we at least assume that a particular 
legal system uses only one conceptual model?
c) If the answer to (b) is no, can I shoot myself now, or do I have to 
wait? (joke)

Tara