mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-04-23 17:15:31 +00:00
Code Activity

Merge branch 'master' of https://github.com/z3prover/z3

Browse source
This commit is contained in:
Nikolaj Bjorner 2018-03-14 09:04:10 -07:00
commit 776a7d4e6c
44 changed files with 315 additions and 399 deletions
Download patch file Download diff file Expand all files Collapse all files

3
src/api/api_ast.cpp
View file

@ -919,7 +919,6 @@ extern "C" {
case PR_REWRITE: return Z3_OP_PR_REWRITE;
case PR_REWRITE_STAR: return Z3_OP_PR_REWRITE_STAR;
case PR_PULL_QUANT: return Z3_OP_PR_PULL_QUANT;
case PR_PULL_QUANT_STAR: return Z3_OP_PR_PULL_QUANT_STAR;
case PR_PUSH_QUANT: return Z3_OP_PR_PUSH_QUANT;
case PR_ELIM_UNUSED_VARS: return Z3_OP_PR_ELIM_UNUSED_VARS;
case PR_DER: return Z3_OP_PR_DER;
@ -936,9 +935,7 @@ extern "C" {
case PR_IFF_OEQ: return Z3_OP_PR_IFF_OEQ;
case PR_NNF_POS: return Z3_OP_PR_NNF_POS;
case PR_NNF_NEG: return Z3_OP_PR_NNF_NEG;
case PR_NNF_STAR: return Z3_OP_PR_NNF_STAR;
case PR_SKOLEMIZE: return Z3_OP_PR_SKOLEMIZE;
case PR_CNF_STAR: return Z3_OP_PR_CNF_STAR;
case PR_MODUS_PONENS_OEQ: return Z3_OP_PR_MODUS_PONENS_OEQ;
case PR_TH_LEMMA: return Z3_OP_PR_TH_LEMMA;
case PR_HYPER_RESOLVE: return Z3_OP_PR_HYPER_RESOLVE;

2
src/api/c++/z3++.h
View file

@ -989,7 +989,7 @@ namespace z3 {
/**
\brief sequence and regular expression operations.
+ is overloaeded as sequence concatenation and regular expression union.
+ is overloaded as sequence concatenation and regular expression union.
concat is overloaded to handle sequences and regular expressions
*/
expr extract(expr const& offset, expr const& length) const {

10
src/api/dotnet/Context.cs
View file

@ -2515,7 +2515,7 @@ namespace Microsoft.Z3
/// <summary>
/// Concatentate sequences.
/// Concatenate sequences.
/// </summary>
public SeqExpr MkConcat(params SeqExpr[] t)
{
@ -3597,7 +3597,7 @@ namespace Microsoft.Z3
}
/// <summary>
/// Create a tactic that fails if the goal is not triviall satisfiable (i.e., empty)
/// Create a tactic that fails if the goal is not trivially satisfiable (i.e., empty)
/// or trivially unsatisfiable (i.e., contains `false').
/// </summary>
public Tactic FailIfNotDecided()
@ -4656,7 +4656,7 @@ namespace Microsoft.Z3
/// Conversion of a floating-point term into a bit-vector.
/// </summary>
/// <remarks>
/// Produces a term that represents the conversion of the floating-poiunt term t into a
/// Produces a term that represents the conversion of the floating-point term t into a
/// bit-vector term of size sz in 2's complement format (signed when signed==true). If necessary,
/// the result will be rounded according to rounding mode rm.
/// </remarks>
@ -4677,7 +4677,7 @@ namespace Microsoft.Z3
/// Conversion of a floating-point term into a real-numbered term.
/// </summary>
/// <remarks>
/// Produces a term that represents the conversion of the floating-poiunt term t into a
/// Produces a term that represents the conversion of the floating-point term t into a
/// real number. Note that this type of conversion will often result in non-linear
/// constraints over real terms.
/// </remarks>
@ -4696,7 +4696,7 @@ namespace Microsoft.Z3
/// <remarks>
/// The size of the resulting bit-vector is automatically determined. Note that
/// IEEE 754-2008 allows multiple different representations of NaN. This conversion
/// knows only one NaN and it will always produce the same bit-vector represenatation of
/// knows only one NaN and it will always produce the same bit-vector representation of
/// that NaN.
/// </remarks>
/// <param name="t">FloatingPoint term.</param>

38
src/api/dotnet/Expr.cs
View file

@ -932,7 +932,7 @@ namespace Microsoft.Z3
/// Indicates whether the term is a proof by condensed transitivity of a relation
/// </summary>
/// <remarks>
/// Condensed transitivity proof. This proof object is only used if the parameter PROOF_MODE is 1.
/// Condensed transitivity proof.
/// It combines several symmetry and transitivity proofs.
/// Example:
/// T1: (R a b)
@ -1035,14 +1035,11 @@ namespace Microsoft.Z3
/// </summary>
/// <remarks>
/// A proof for rewriting an expression t into an expression s.
/// This proof object is used if the parameter PROOF_MODE is 1.
/// This proof object can have n antecedents.
/// The antecedents are proofs for equalities used as substitution rules.
/// The object is also used in a few cases if the parameter PROOF_MODE is 2.
/// The cases are:
/// The object is used in a few cases:
/// - When applying contextual simplification (CONTEXT_SIMPLIFIER=true)
/// - When converting bit-vectors to Booleans (BIT2BOOL=true)
/// - When pulling ite expression up (PULL_CHEAP_ITE_TREES=true)
/// </remarks>
public bool IsProofRewriteStar { get { return IsApp && FuncDecl.DeclKind == Z3_decl_kind.Z3_OP_PR_REWRITE_STAR; } }
@ -1054,15 +1051,6 @@ namespace Microsoft.Z3
/// </remarks>
public bool IsProofPullQuant { get { return IsApp && FuncDecl.DeclKind == Z3_decl_kind.Z3_OP_PR_PULL_QUANT; } }
/// <summary>
/// Indicates whether the term is a proof for pulling quantifiers out.
/// </summary>
/// <remarks>
/// A proof for (iff P Q) where Q is in prenex normal form.
/// This proof object is only used if the parameter PROOF_MODE is 1.
/// This proof object has no antecedents
/// </remarks>
public bool IsProofPullQuantStar { get { return IsApp && FuncDecl.DeclKind == Z3_decl_kind.Z3_OP_PR_PULL_QUANT_STAR; } }
/// <summary>
/// Indicates whether the term is a proof for pushing quantifiers in.
@ -1304,28 +1292,6 @@ namespace Microsoft.Z3
/// </remarks>
public bool IsProofNNFNeg { get { return IsApp && FuncDecl.DeclKind == Z3_decl_kind.Z3_OP_PR_NNF_NEG; } }
/// <summary>
/// Indicates whether the term is a proof for (~ P Q) here Q is in negation normal form.
/// </summary>
/// <remarks>
/// A proof for (~ P Q) where Q is in negation normal form.
///
/// This proof object is only used if the parameter PROOF_MODE is 1.
///
/// This proof object may have n antecedents. Each antecedent is a PR_DEF_INTRO.
/// </remarks>
public bool IsProofNNFStar { get { return IsApp && FuncDecl.DeclKind == Z3_decl_kind.Z3_OP_PR_NNF_STAR; } }
/// <summary>
/// Indicates whether the term is a proof for (~ P Q) where Q is in conjunctive normal form.
/// </summary>
/// <remarks>
/// A proof for (~ P Q) where Q is in conjunctive normal form.
/// This proof object is only used if the parameter PROOF_MODE is 1.
/// This proof object may have n antecedents. Each antecedent is a PR_DEF_INTRO.
/// </remarks>
public bool IsProofCNFStar { get { return IsApp && FuncDecl.DeclKind == Z3_decl_kind.Z3_OP_PR_CNF_STAR; } }
/// <summary>
/// Indicates whether the term is a proof for a Skolemization step
/// </summary>

10
src/api/java/Context.java
View file

@ -1978,7 +1978,7 @@ public class Context implements AutoCloseable {
}
/**
* Concatentate sequences.
* Concatenate sequences.
*/
public SeqExpr mkConcat(SeqExpr... t)
{
@ -2782,7 +2782,7 @@ public class Context implements AutoCloseable {
}
/**
* Create a tactic that fails if the goal is not triviall satisfiable (i.e.,
* Create a tactic that fails if the goal is not trivially satisfiable (i.e.,
* empty) or trivially unsatisfiable (i.e., contains `false').
**/
public Tactic failIfNotDecided()
@ -3770,7 +3770,7 @@ public class Context implements AutoCloseable {
* @param sz Size of the resulting bit-vector.
* @param signed Indicates whether the result is a signed or unsigned bit-vector.
* Remarks:
* Produces a term that represents the conversion of the floating-poiunt term t into a
* Produces a term that represents the conversion of the floating-point term t into a
* bit-vector term of size sz in 2's complement format (signed when signed==true). If necessary,
* the result will be rounded according to rounding mode rm.
* @throws Z3Exception
@ -3787,7 +3787,7 @@ public class Context implements AutoCloseable {
* Conversion of a floating-point term into a real-numbered term.
* @param t FloatingPoint term
* Remarks:
* Produces a term that represents the conversion of the floating-poiunt term t into a
* Produces a term that represents the conversion of the floating-point term t into a
* real number. Note that this type of conversion will often result in non-linear
* constraints over real terms.
* @throws Z3Exception
@ -3803,7 +3803,7 @@ public class Context implements AutoCloseable {
* Remarks:
* The size of the resulting bit-vector is automatically determined. Note that
* IEEE 754-2008 allows multiple different representations of NaN. This conversion
* knows only one NaN and it will always produce the same bit-vector represenatation of
* knows only one NaN and it will always produce the same bit-vector representation of
* that NaN.
* @throws Z3Exception
**/

55
src/api/java/Expr.java
View file

@ -1398,8 +1398,7 @@ public class Expr extends AST
/**
* Indicates whether the term is a proof by condensed transitivity of a
* relation
* Remarks: Condensed transitivity proof. This proof object is
* only used if the parameter PROOF_MODE is 1. It combines several symmetry
* Remarks: Condensed transitivity proof. It combines several symmetry
* and transitivity proofs. Example: T1: (R a b) T2: (R c b) T3: (R c d)
* [trans* T1 T2 T3]: (R a d) R must be a symmetric and transitive relation.
*
@ -1506,14 +1505,11 @@ public class Expr extends AST
/**
* Indicates whether the term is a proof by rewriting
* Remarks: A proof for
* rewriting an expression t into an expression s. This proof object is used
* if the parameter PROOF_MODE is 1. This proof object can have n
* rewriting an expression t into an expression s. This proof object can have n
* antecedents. The antecedents are proofs for equalities used as
* substitution rules. The object is also used in a few cases if the
* parameter PROOF_MODE is 2. The cases are: - When applying contextual
* substitution rules. The object is used in a few cases . The cases are: - When applying contextual
* simplification (CONTEXT_SIMPLIFIER=true) - When converting bit-vectors to
* Booleans (BIT2BOOL=true) - When pulling ite expression up
* (PULL_CHEAP_ITE_TREES=true)
* Booleans (BIT2BOOL=true)
* @throws Z3Exception on error
* @return a boolean
**/
@ -1534,17 +1530,6 @@ public class Expr extends AST
return isApp() && getFuncDecl().getDeclKind() == Z3_decl_kind.Z3_OP_PR_PULL_QUANT;
}
/**
* Indicates whether the term is a proof for pulling quantifiers out.
*
* Remarks: A proof for (iff P Q) where Q is in prenex normal form. This * proof object is only used if the parameter PROOF_MODE is 1. This proof * object has no antecedents
* @throws Z3Exception on error
* @return a boolean
**/
public boolean isProofPullQuantStar()
{
return isApp() && getFuncDecl().getDeclKind() == Z3_decl_kind.Z3_OP_PR_PULL_QUANT_STAR;
}
/**
* Indicates whether the term is a proof for pushing quantifiers in.
@ -1804,38 +1789,6 @@ public class Expr extends AST
return isApp() && getFuncDecl().getDeclKind() == Z3_decl_kind.Z3_OP_PR_NNF_NEG;
}
/**
* Indicates whether the term is a proof for (~ P Q) here Q is in negation
* normal form.
* Remarks: A proof for (~ P Q) where Q is in negation normal
* form.
*
* This proof object is only used if the parameter PROOF_MODE is 1.
*
* This proof object may have n antecedents. Each antecedent is a
* PR_DEF_INTRO.
* @throws Z3Exception on error
* @return a boolean
**/
public boolean isProofNNFStar()
{
return isApp() && getFuncDecl().getDeclKind() == Z3_decl_kind.Z3_OP_PR_NNF_STAR;
}
/**
* Indicates whether the term is a proof for (~ P Q) where Q is in
* conjunctive normal form.
* Remarks: A proof for (~ P Q) where Q is in
* conjunctive normal form. This proof object is only used if the parameter
* PROOF_MODE is 1. This proof object may have n antecedents. Each
* antecedent is a PR_DEF_INTRO.
* @throws Z3Exception on error
* @return a boolean
**/
public boolean isProofCNFStar()
{
return isApp() && getFuncDecl().getDeclKind() == Z3_decl_kind.Z3_OP_PR_CNF_STAR;
}
/**
* Indicates whether the term is a proof for a Skolemization step

3
src/api/ml/z3.ml
View file

@ -1402,7 +1402,6 @@ struct
let is_rewrite (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_REWRITE)
let is_rewrite_star (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_REWRITE_STAR)
let is_pull_quant (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_PULL_QUANT)
let is_pull_quant_star (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_PULL_QUANT_STAR)
let is_push_quant (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_PUSH_QUANT)
let is_elim_unused_vars (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_ELIM_UNUSED_VARS)
let is_der (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_DER)
@ -1419,8 +1418,6 @@ struct
let is_iff_oeq (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_IFF_OEQ)
let is_nnf_pos (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_NNF_POS)
let is_nnf_neg (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_NNF_NEG)
let is_nnf_star (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_NNF_STAR)
let is_cnf_star (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_CNF_STAR)
let is_skolemize (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_SKOLEMIZE)
let is_modus_ponens_oeq (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_MODUS_PONENS_OEQ)
let is_theory_lemma (x:expr) = (AST.is_app x) && (FuncDecl.get_decl_kind (Expr.get_func_decl x) = OP_PR_TH_LEMMA)

12
src/api/python/z3/z3.py
View file

@ -2428,7 +2428,7 @@ def is_rational_value(a):
return is_arith(a) and a.is_real() and _is_numeral(a.ctx, a.as_ast())
def is_algebraic_value(a):
"""Return `True` if `a` is an algerbraic value of sort Real.
"""Return `True` if `a` is an algebraic value of sort Real.
>>> is_algebraic_value(RealVal("3/5"))
False
@ -4437,7 +4437,7 @@ class Datatype:
"""Declare constructor named `name` with the given accessors `args`.
Each accessor is a pair `(name, sort)`, where `name` is a string and `sort` a Z3 sort or a reference to the datatypes being declared.
In the followin example `List.declare('cons', ('car', IntSort()), ('cdr', List))`
In the following example `List.declare('cons', ('car', IntSort()), ('cdr', List))`
declares the constructor named `cons` that builds a new List using an integer and a List.
It also declares the accessors `car` and `cdr`. The accessor `car` extracts the integer of a `cons` cell,
and `cdr` the list of a `cons` cell. After all constructors were declared, we use the method create() to create
@ -4457,7 +4457,7 @@ class Datatype:
return "Datatype(%s, %s)" % (self.name, self.constructors)
def create(self):
"""Create a Z3 datatype based on the constructors declared using the mehtod `declare()`.
"""Create a Z3 datatype based on the constructors declared using the method `declare()`.
The function `CreateDatatypes()` must be used to define mutually recursive datatypes.
@ -8874,7 +8874,7 @@ class FPNumRef(FPRef):
def isSubnormal(self):
return Z3_fpa_is_numeral_subnormal(self.ctx.ref(), self.as_ast())
"""Indicates whether the numeral is postitive."""
"""Indicates whether the numeral is positive."""
def isPositive(self):
return Z3_fpa_is_numeral_positive(self.ctx.ref(), self.as_ast())
@ -9670,7 +9670,7 @@ def fpToIEEEBV(x, ctx=None):
The size of the resulting bit-vector is automatically determined.
Note that IEEE 754-2008 allows multiple different representations of NaN. This conversion
knows only one NaN and it will always produce the same bit-vector represenatation of
knows only one NaN and it will always produce the same bit-vector representation of
that NaN.
>>> x = FP('x', FPSort(8, 24))
@ -9845,7 +9845,7 @@ def Empty(s):
raise Z3Exception("Non-sequence, non-regular expression sort passed to Empty")
def Full(s):
"""Create the regular expression that accepts the universal langauge
"""Create the regular expression that accepts the universal language
>>> e = Full(ReSort(SeqSort(IntSort())))
>>> print(e)
re.all

3
src/api/z3.h
View file

@ -21,7 +21,8 @@ Notes:
#ifndef Z3_H_
#define Z3_H_
#include<stdio.h>
#include <stdio.h>
#include <stdbool.h>
#include "z3_macros.h"
#include "z3_api.h"
#include "z3_ast_containers.h"

28
src/api/z3_api.h
View file

@ -459,7 +459,7 @@ typedef enum
[trans T1 T2]: (R t u)
}
- Z3_OP_PR_TRANSITIVITY_STAR: Condensed transitivity proof. This proof object is only used if the parameter PROOF_MODE is 1.
- Z3_OP_PR_TRANSITIVITY_STAR: Condensed transitivity proof.
It combines several symmetry and transitivity proofs.
Example:
@ -539,21 +539,14 @@ typedef enum
}
- Z3_OP_PR_REWRITE_STAR: A proof for rewriting an expression t into an expression s.
This proof object is used if the parameter PROOF_MODE is 1.
This proof object can have n antecedents.
The antecedents are proofs for equalities used as substitution rules.
The object is also used in a few cases if the parameter PROOF_MODE is 2.
The cases are:
The proof rule is used in a few cases. The cases are:
- When applying contextual simplification (CONTEXT_SIMPLIFIER=true)
- When converting bit-vectors to Booleans (BIT2BOOL=true)
- When pulling ite expression up (PULL_CHEAP_ITE_TREES=true)
- Z3_OP_PR_PULL_QUANT: A proof for (iff (f (forall (x) q(x)) r) (forall (x) (f (q x) r))). This proof object has no antecedents.
- Z3_OP_PR_PULL_QUANT_STAR: A proof for (iff P Q) where Q is in prenex normal form.
This proof object is only used if the parameter PROOF_MODE is 1.
This proof object has no antecedents.
- Z3_OP_PR_PUSH_QUANT: A proof for:
\nicebox{
@ -726,15 +719,6 @@ typedef enum
[nnf-neg T1 T2 T3 T4]: (~ (not (iff s_1 s_2))
(and (or r_1 r_2) (or r_1' r_2')))
}
- Z3_OP_PR_NNF_STAR: A proof for (~ P Q) where Q is in negation normal form.
This proof object is only used if the parameter PROOF_MODE is 1.
This proof object may have n antecedents. Each antecedent is a PR_DEF_INTRO.
- Z3_OP_PR_CNF_STAR: A proof for (~ P Q) where Q is in conjunctive normal form.
This proof object is only used if the parameter PROOF_MODE is 1.
This proof object may have n antecedents. Each antecedent is a PR_DEF_INTRO.
- Z3_OP_PR_SKOLEMIZE: Proof for:
@ -1142,7 +1126,6 @@ typedef enum {
Z3_OP_PR_REWRITE,
Z3_OP_PR_REWRITE_STAR,
Z3_OP_PR_PULL_QUANT,
Z3_OP_PR_PULL_QUANT_STAR,
Z3_OP_PR_PUSH_QUANT,
Z3_OP_PR_ELIM_UNUSED_VARS,
Z3_OP_PR_DER,
@ -1159,8 +1142,6 @@ typedef enum {
Z3_OP_PR_IFF_OEQ,
Z3_OP_PR_NNF_POS,
Z3_OP_PR_NNF_NEG,
Z3_OP_PR_NNF_STAR,
Z3_OP_PR_CNF_STAR,
Z3_OP_PR_SKOLEMIZE,
Z3_OP_PR_MODUS_PONENS_OEQ,
Z3_OP_PR_TH_LEMMA,
@ -1477,7 +1458,6 @@ extern "C" {
/*@{*/
/**
\deprecated
\brief Create a configuration object for the Z3 context object.
Configurations are created in order to assign parameters prior to creating
@ -1510,7 +1490,6 @@ extern "C" {
Z3_config Z3_API Z3_mk_config(void);
/**
\deprecated
\brief Delete the given configuration object.
\sa Z3_mk_config
@ -1520,7 +1499,6 @@ extern "C" {
void Z3_API Z3_del_config(Z3_config c);
/**
\deprecated
\brief Set a configuration parameter.
The following parameters can be set for
@ -1537,7 +1515,6 @@ extern "C" {
/*@{*/
/**
\deprecated
\brief Create a context using the given configuration.
After a context is created, the configuration cannot be changed,
@ -1617,7 +1594,6 @@ extern "C" {
void Z3_API Z3_dec_ref(Z3_context c, Z3_ast a);
/**
\deprecated
\brief Set a value of a context parameter.
\sa Z3_global_param_set

8
src/api/z3_fpa.h
View file

@ -756,7 +756,7 @@ extern "C" {
/**
\brief Conversion of a floating-point term into an unsigned bit-vector.
Produces a term that represents the conversion of the floating-poiunt term t into a
Produces a term that represents the conversion of the floating-point term t into a
bit-vector term of size sz in unsigned 2's complement format. If necessary, the result
will be rounded according to rounding mode rm.
@ -772,7 +772,7 @@ extern "C" {
/**
\brief Conversion of a floating-point term into a signed bit-vector.
Produces a term that represents the conversion of the floating-poiunt term t into a
Produces a term that represents the conversion of the floating-point term t into a
bit-vector term of size sz in signed 2's complement format. If necessary, the result
will be rounded according to rounding mode rm.
@ -788,7 +788,7 @@ extern "C" {
/**
\brief Conversion of a floating-point term into a real-numbered term.
Produces a term that represents the conversion of the floating-poiunt term t into a
Produces a term that represents the conversion of the floating-point term t into a
real number. Note that this type of conversion will often result in non-linear
constraints over real terms.
@ -1011,7 +1011,7 @@ extern "C" {
determined.
Note that IEEE 754-2008 allows multiple different representations of NaN. This conversion
knows only one NaN and it will always produce the same bit-vector represenatation of
knows only one NaN and it will always produce the same bit-vector representation of
that NaN.
def_API('Z3_mk_fpa_to_ieee_bv', AST, (_in(CONTEXT),_in(AST)))

4
src/api/z3_interp.h
View file

@ -98,7 +98,7 @@ extern "C" {
Interpolant may not necessarily be computable from all
proofs. To be sure an interpolant can be computed, the proof
must be generated by an SMT solver for which interpoaltion is
must be generated by an SMT solver for which interpolation is
supported, and the premises must be expressed using only
theories and operators for which interpolation is supported.
@ -199,7 +199,7 @@ extern "C" {
(implies (and c1 ... cn f) v)
where c1 .. cn are the children of v (which must precede v in the file)
and f is the formula assiciated to node v. The last formula in the
and f is the formula associated to node v. The last formula in the
file is the root vertex, and is represented by the predicate "false".
A solution to a tree interpolation problem can be thought of as a