simplify
Testing & QualityReduce formula complexity using Z3 tactic chains. Supports configurable tactic pipelines for boolean, arithmetic, and bitvector simplification.
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How to use this skill
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Given a formula, apply a sequence of Z3 tactics to produce an equivalent but simpler form. This is useful for understanding what Z3 sees after preprocessing, debugging tactic selection, and reducing formula size before solving.
Step 1: Choose tactics
Action: Select a tactic chain from the available Z3 tactics based on the formula's theory.
Expectation: A comma-separated list of tactic names suitable for the formula domain.
Result:
If unsure, use the default chain: simplify,propagate-values,ctx-simplify.
For bitvector formulas, add bit-blast. Proceed to Step 2.
| Tactic | What it does |
|---|---|
| simplify | constant folding, algebraic identities |
| propagate-values | substitute known equalities |
| ctx-simplify | context-dependent simplification |
| elim-uncnstr | remove unconstrained variables |
| solve-eqs | Gaussian elimination |
| bit-blast | reduce bitvectors to booleans |
| tseitin-cnf | convert to CNF |
| aig | and-inverter graph reduction |
Step 2: Run simplification
Action: Invoke simplify.py with the formula and optional tactic chain.
Expectation: The script applies each tactic in sequence and prints the simplified formula. A run entry is logged to z3agent.db.
Result: If the output is simpler, pass it to solve or prove. If unchanged, try a different tactic chain.
python3 scripts/simplify.py --formula "(assert (and (> x 0) (> x 0)))" --vars "x:Int"
python3 scripts/simplify.py --file formula.smt2 --tactics "simplify,propagate-values,ctx-simplify"
python3 scripts/simplify.py --file formula.smt2 --debug
Without --tactics, the script applies the default chain: simplify, propagate-values, ctx-simplify.
Step 3: Interpret the output
Action: Read the simplified formula output in SMT-LIB2 syntax.
Expectation:
One or more (assert ...) blocks representing equivalent subgoals.
Result: A smaller formula indicates successful reduction. Pass the result to solve, prove, or optimize as needed.
Parameters
| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
| formula | string | no | SMT-LIB2 formula to simplify | |
| vars | string | no | variable declarations as "name:sort" pairs | |
| file | path | no | path to .smt2 file | |
| tactics | string | no | simplify,propagate-values,ctx-simplify | comma-separated tactic names |
| timeout | int | no | 30 | seconds |
| z3 | path | no | auto | path to z3 binary |
| debug | flag | no | off | verbose tracing |
| db | path | no | .z3-agent/z3agent.db | logging database |