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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
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Nikolaj Bjorner 2018-10-14 15:16:22 -07:00
commit e9d615e309
204 changed files with 4620 additions and 2435 deletions
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31
src/sat/sat_params.pyg
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@ -15,7 +15,7 @@ def_module_params('sat',
('restart.margin', DOUBLE, 1.1, 'margin between fast and slow restart factors. For ema'),
('restart.emafastglue', DOUBLE, 3e-2, 'ema alpha factor for fast moving average'),
('restart.emaslowglue', DOUBLE, 1e-5, 'ema alpha factor for slow moving average'),
('variable_decay', UINT, 110, 'multiplier (divided by 100) for the VSIDS activity increement'),
('variable_decay', UINT, 110, 'multiplier (divided by 100) for the VSIDS activity increment'),
('inprocess.max', UINT, UINT_MAX, 'maximal number of inprocessing passes'),
('branching.heuristic', SYMBOL, 'vsids', 'branching heuristic vsids, lrb or chb'),
('branching.anti_exploration', BOOL, False, 'apply anti-exploration heuristic for branch selection'),
@ -31,6 +31,7 @@ def_module_params('sat',
('gc.burst', BOOL, False, 'perform eager garbage collection during initialization'),
('gc.defrag', BOOL, True, 'defragment clauses when garbage collecting'),
('simplify.delay', UINT, 0, 'set initial delay of simplification by a conflict count'),
('force_cleanup', BOOL, False, 'force cleanup to remove tautologies and simplify clauses'),
('minimize_lemmas', BOOL, True, 'minimize learned clauses'),
('dyn_sub_res', BOOL, True, 'dynamic subsumption resolution for minimizing learned clauses'),
('core.minimize', BOOL, False, 'minimize computed core'),
@ -52,17 +53,39 @@ def_module_params('sat',
('unit_walk', BOOL, False, 'use unit-walk search instead of CDCL'),
('unit_walk_threads', UINT, 0, 'number of unit-walk search threads to find satisfiable solution'),
('lookahead.cube.cutoff', SYMBOL, 'depth', 'cutoff type used to create lookahead cubes: depth, freevars, psat, adaptive_freevars, adaptive_psat'),
# - depth: the maximal cutoff is fixed to the value of lookahead.cube.depth.
# So if the value is 10, at most 1024 cubes will be generated of length 10.
# - freevars: cutoff based on a variable fraction of lookahead.cube.freevars.
# Cut if the number of current unassigned variables drops below a fraction of number of initial variables.
# - psat: Let psat_heur := (Sum_{clause C} (psat.clause_base ^ {-|C|+1})) / |freevars|^psat.var_exp
# Cut if the value of psat_heur exceeds psat.trigger
# - adaptive_freevars: Cut if the number of current unassigned variables drops below a fraction of free variables
# at the time of the last conflict. The fraction is increased every time the cutoff is created.
# - adative_psat: Cut based on psat_heur in an adaptive way.
('lookahead.cube.fraction', DOUBLE, 0.4, 'adaptive fraction to create lookahead cubes. Used when lookahead.cube.cutoff is adaptive_freevars or adaptive_psat'),
('lookahead.cube.depth', UINT, 1, 'cut-off depth to create cubes. Used when lookahead.cube.cutoff is depth.'),
('lookahead.cube.freevars', DOUBLE, 0.8, 'cube free fariable fraction. Used when lookahead.cube.cutoff is freevars'),
('lookahead.cube.freevars', DOUBLE, 0.8, 'cube free variable fraction. Used when lookahead.cube.cutoff is freevars'),
('lookahead.cube.psat.var_exp', DOUBLE, 1, 'free variable exponent for PSAT cutoff'),
('lookahead.cube.psat.clause_base', DOUBLE, 2, 'clause base for PSAT cutoff'),
('lookahead.cube.psat.trigger', DOUBLE, 5, 'trigger value to create lookahead cubes for PSAT cutoff. Used when lookahead.cube.cutoff is psat'),
('lookahead_search', BOOL, False, 'use lookahead solver'),
('lookahead.preselect', BOOL, False, 'use pre-selection of subset of variables for branching'),
('lookahead_simplify', BOOL, False, 'use lookahead solver during simplification'),
('lookahead.use_learned', BOOL, False, 'use learned clauses when selecting lookahead literal'),
('lookahead_simplify.bca', BOOL, True, 'add learned binary clauses as part of lookahead simplification'),
('lookahead.global_autarky', BOOL, False, 'prefer to branch on variables that occur in clauses that are reduced'),
('lookahead.reward', SYMBOL, 'march_cu', 'select lookahead heuristic: ternary, heule_schur (Heule Schur), heuleu (Heule Unit), unit, or march_cu')))
('lookahead.reward', SYMBOL, 'march_cu', 'select lookahead heuristic: ternary, heule_schur (Heule Schur), heuleu (Heule Unit), unit, or march_cu'))
# reward function used to determine which literal to cube on.
# - ternary: reward function useful for random 3-SAT instances. Used by Heule and Knuth in March.
# - heule_schur: reward function based on "Schur Number 5", Heule, AAAI 2018
# The score of a literal lit is:
# Sum_{C in Clauses | lit in C} 2 ^ (- |C|+1)
# * Sum_{lit' in C | lit' != lit} lit_occs(~lit')
# / | C |
# where lit_occs(lit) is the number of clauses containing lit.
# - heuleu: The score of a literal lit is: Sum_{C in Clauses | lit in C} 2 ^ (-|C| + 1)
# - unit: heule_schur + also counts number of unit clauses.
# - march_cu: default reward function used in a version of March
# Each reward function also comes with its own variant of "mix_diff", which
# is the function for combining reward metrics for the positive and negative variant of a literal.
)