mirror of
https://github.com/Z3Prover/z3
synced 2025-04-28 11:25:51 +00:00
72 lines
1.4 KiB
C++
72 lines
1.4 KiB
C++
/*++
|
|
Copyright (c) 2011 Microsoft Corporation
|
|
|
|
Module Name:
|
|
|
|
nnf_tactic.h
|
|
|
|
Abstract:
|
|
|
|
NNF tactic
|
|
|
|
Author:
|
|
|
|
Leonardo de Moura (leonardo) 2011-12-28.
|
|
|
|
Note:
|
|
|
|
tactic documentation below co-created using gptchat (with some corrections) :-)
|
|
|
|
Tactic Documentation:
|
|
|
|
## Tactic nnf
|
|
|
|
### Short Description:
|
|
|
|
The tactic converts formulas to negation normal form (NNF)
|
|
|
|
### Long Description
|
|
|
|
In NNF, negations only appear in front of atomic formulas.
|
|
|
|
Standard rules for conversion into negation normal form are:
|
|
- `(not (and p q))` is converted to `(or (not p) (not q))`
|
|
- `(not (or p q))` is converted to `(and (not p) (not q))`
|
|
- `(not (not p))` is converted to `p`
|
|
- `(not (exists x. p))` is converted to `(forall x. (not p))`
|
|
- `(not (forall x. p))` is converted to `(exists x. (not p))`
|
|
|
|
|
|
Once all negations are pushed inside, the resulting formula is in NNF.
|
|
|
|
### Example
|
|
|
|
```z3
|
|
(declare-const x Int)
|
|
(assert (not (or (> x 0) (< x 0))))
|
|
(apply nnf)
|
|
```
|
|
|
|
|
|
### Notes
|
|
|
|
* supports unsat cores, proof terms
|
|
|
|
|
|
|
|
--*/
|
|
#pragma once
|
|
|
|
#include "util/params.h"
|
|
class ast_manager;
|
|
class tactic;
|
|
|
|
tactic * mk_snf_tactic(ast_manager & m, params_ref const & p = params_ref());
|
|
tactic * mk_nnf_tactic(ast_manager & m, params_ref const & p = params_ref());
|
|
|
|
/*
|
|
ADD_TACTIC("snf", "put goal in skolem normal form.", "mk_snf_tactic(m, p)")
|
|
ADD_TACTIC("nnf", "put goal in negation normal form.", "mk_nnf_tactic(m, p)")
|
|
*/
|
|
|
|
|