- increase build version to 4.12.1. This prepares updated release for MacOs-11 build on x86
- move literal propagation mode in euf-egraph to a callback and traversal of equivalence class. Track antecedent by newest equality instead of root. This makes equality propagation to literals have similar behavior as in legacy solver and appears to result in a speedup (10% fewer conflicts on QF_UF/QG-classification/qg5/iso_icl478.smt2 in preliminary testing)
- fix interaction of pre-processing and assumptions. Pre-processing has to freeze assumption literals so they don't get eliminated. This is similar to dependencies that are already frozen.
- add sat.smt option to enable the new incremental core (it is not ready for mainstream consumption as cloning and other features are not implemented and it hasn't been tested in any detail yet).
- move "name" into attribute on simplifier so it can be reused for diagnostics by the seq-simplifier.
other updates:
- change signature of advance_qhead to simplify call sites
- have model reconstruction replay work on a tail of dependent_expr state, while adding formulas to the tail.
literals true/false are not necessarily created when the merge flag is set.
Also disable merge_tf for if-then-else expressions
Perhaps even not insert children of if expressions into congruence table?
perf fix for propagation behavior for equalities in the new core.
The old behavior was not to allow congruence closure on equalities.
The new behavior is to just not allow merging tf with equalities unless they appear somewhere in a foreign context (not under a Boolean operator)
The change re-surfaces merge_tf and enable_cgc distinction from the old core.
They can both be turned on or off.
merge_enabled renamed to cgc_enabled
The change is highly likely to introduce regressions in the new core.
Change propagation of literals from congruence:
- track antecedent enode. There are four ways to propagate
literals from the egraph.
- the literal is an equality and the two arguments are congruent
- the antecedent is merged with node n and the antecedent has a Boolean variable assignment.
- the antecedent is true or false, they are merged.
- the merge_tf flag is toggled to true but the node n has not been merged with true/false
