Fix a small problem with triggers on spec_fn closures and deprecate triggers on spec_fn closures #1038
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This is related to #331 and #1033 . It fixes the minor problem from #1033 . However, looking at this more closely, I think manual triggers on spec_fn closures cannot be supported in general because the AIR-generated axiom for spec_fn closures quantifies over "holes" that are not visible to source-level quantifiers. The built-in trigger generated by AIR works fine with these holes, but manual triggers do not because they have no way to name the holes. The examples in #331 happened to work because there were 0 holes in those examples, but for more complex cases (like the one in #1033 ), the manual triggers just lead to a Z3 warning "WARNING ... pattern does not contain all quantified variables" and are subsequently dropped by Z3. Therefore, I believe that this feature (manual triggers on spec_fn closures) should be deprecated. The discussion in #331 provides a way to work around the absence of this feature.