[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[tlaplus] Re: model value

Oh,I see. Thank you for your answer.

在2022年1月27日星期四 UTC+8 22:42:30<andrew...@xxxxxxxxx> 写道:
Good question. There are a few ways to do this, assuming your model values {v1, v2, ... vn} are in a constant called Value, and your spec is called SpecName.tla:
  • Have a separate constant called Rank which is a function you define of type [Value -> Nat], and use this whenever comparing model values in your spec (so instead of v1 < v1 it's Rank[v1] < Rank[v2]). See here for how you can define the value of Rank in your model.
  • If the rank is arbitrary, you could skip having to define the value of Rank by hand and write a separate MCSpecName.tla spec that includes SpecName.tla with INSTANCE and instantiates Rank using an arbitrary order function created with CHOOSE.
  • If you want to be fancy you could declare CONSTANT _ \preceq _ in SpecName.tla and define its value in MCSpecName.tla with INSTANCE SpecName WITH \preceq <- LAMBDA a, b : Rank[a] <= Rank[b]. Then in SpecName.tla you can naturally compare v1 \preceq v1. You could of course use CONSTANT _ <= _ but this is likely to conflict with the definition of <= if you import Nat or Int.

On Thursday, January 27, 2022 at 7:52:28 AM UTC-5 jiaojiao cai wrote:
Can I artificially define the size order for model values like Integer? For example, v1 is less than v2,v2 is less than v3。
If yes, how can l do it?

You received this message because you are subscribed to the Google Groups "tlaplus" group.
To unsubscribe from this group and stop receiving emails from it, send an email to tlaplus+unsubscribe@xxxxxxxxxxxxxxxx.
To view this discussion on the web visit https://groups.google.com/d/msgid/tlaplus/dda723a9-c402-46b7-8921-c6a4f01acf3en%40googlegroups.com.