simplifiers layer is a common substrate for global non-incremental and incremental processing.
The first two layers are new, but others are to be ported form tactics.
- bv::slice - rewrites equations to cut-dice-slice bit-vector extractions until they align. It creates opportunities for rewriting portions of bit-vectors to common sub-expressions, including values.
- euf::completion - generalizes the KB simplifcation from asserted formulas to use the E-graph to establish a global and order-independent canonization.
The interface dependent_expr_simplifier is amenable to forming tactics. Plugins for asserted-formulas is also possible but not yet realized.
- ensure mk_extract performs simplification to distribute over extract and removing extract if the range is the entire bit-vector
- ensure bool_rewriter simplifeis disjunctions when applicable.
Removing ternary clause optimization from sat_solver simplifies special case handling of ternary clauses throughout the sat solver and dependent solvers (pb_solver). Benchmarking on QF_BV suggests the ternary clause optimization does not have any effect. While removing ternary clause optimization two bugs in unit propagation were also uncovered: it missed propagations when the only a single undef literal remained in the non-watched literals and it did not update blocked literals in cases where it could in the watch list. These performance bugs were for general clauses, ternary clause propagation did not miss propagations (and don't use blocked literals), but fixing these issues for general clauses appear to have made ternary clause optimization irrelevant based on what was measured.
* Allow reseting the stream of smt2::scanner
* Put the parser of parse_smt2_commands in the cmd_context
* Move parser streams to cmd_context
* Move parser fields from cmd_context to api::context
* Move forward declarations from cmd_context.h to api_context.h
* Change parse_smt2_commands_with_parser to use *& instead of **
* Add tests for Z3_eval_smtlib2_string
* Don't reuse the streams in Z3_eval_smtlib2_string
* Fix indentation
* Add back unnecessary deleted line
Co-authored-by: Nuno Lopes <nuno.lopes@tecnico.ulisboa.pt>
gc-ing definitions leads to unsoundness when they are not replayed.
Instead of attempting to replay definitions theory internalization is irredundant by default.
This is also the old solver behavior where TH_LEMMA is essentially never used, but is valid for top-level theory lemmas.
So far the format is
(forall ((x Int)) body) (not (body[t/x]))
The alternative could be the clause
(not (forall ((x Int)) body)) body[t/x]
they just better be consistent between engines
