Usually in SAT solving, the conflict clause has at least two false literals at the max level (otherwise, the last literal would have been propagated at an earlier level).
But here we are adding clauses on demand; so after backtracking we may have the case that the conflict clause has exactly one undefined literal that must be propagated explicitly.
Add the ability to customize incremental pre-processing simplification for the SMTLIB2 front-end. The main new capability is to use pre-processing tactics in incremental mode that were previously not available. The main new capabilities are
- solve-eqs
- reduce-args
- elim-unconstrained
There are several more. Documentation and exposed simplifiers are populated incrementally. The current set of supported simplifiers can be inspected by using z3 with the --simplifiers flag or referring to https://microsoft.github.io/z3guide/docs/strategies/simplifiers
Some pending features are:
- add the ability to update parameters to simplifiers similar to how tactics can be controlled using parameters.
- expose simplification solvers over the binary API.
move sat_smt_preprocess to solver
fix bugs in model_reconstruction_trail for dependency replay
This is a preparatory step for exposing pre-processing as tactics.
this update enables new incremental linear axioms based on division terms.
It also consolidates some of the backtracking state in nla_core / emons to use stack traces instead of custom backtracking state.
- convert reduce-args to a simplifier. Currently exposed as reduce-args2 tactic until the old tactic code gets removed.
- bug fixes in model_reconstruction trail
- allow multiple defs to be added with same pool of removed formulas
- fix tracking of function symbols instead of expressions to filter replay
- add nla_divisions to track (cheap) divisibility lemmas.
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