anthem-rs/src/problem.rs

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pub enum StatementKind
{
Axiom,
Assumption,
Lemma(crate::ProofDirection),
Assertion,
}
#[derive(Copy, Clone, Eq, PartialEq)]
enum ProofStatus
{
AssumedProven,
ToProve,
}
pub enum ProofResult
{
Proven,
NotProven,
Disproven,
}
pub struct Statement
{
kind: StatementKind,
name: Option<String>,
description: Option<String>,
formula: foliage::Formula,
proof_status: ProofStatus,
}
type VariableDeclarationIDs
= std::collections::BTreeMap::<std::rc::Rc<foliage::VariableDeclaration>, usize>;
struct FormatContext<'a, 'b>
{
pub program_variable_declaration_ids: std::cell::RefCell<VariableDeclarationIDs>,
pub integer_variable_declaration_ids: std::cell::RefCell<VariableDeclarationIDs>,
pub input_constant_declaration_domains: &'a crate::InputConstantDeclarationDomains,
pub variable_declaration_domains: &'b VariableDeclarationDomains,
}
impl Statement
{
pub fn new(kind: StatementKind, formula: foliage::Formula) -> Self
{
Self
{
kind,
name: None,
description: None,
formula,
proof_status: ProofStatus::ToProve,
}
}
pub fn with_name(mut self, name: String) -> Self
{
self.name = Some(name);
self
}
pub fn with_description(mut self, description: String) -> Self
{
self.description = Some(description);
self
}
}
#[derive(Clone, Copy, Eq, Ord, PartialEq, PartialOrd)]
pub enum SectionKind
{
CompletedDefinitions,
IntegrityConstraints,
Axioms,
Assumptions,
Lemmas,
Assertions,
}
type VariableDeclarationDomains
= std::collections::BTreeMap<std::rc::Rc<foliage::VariableDeclaration>, crate::Domain>;
pub struct Problem
{
function_declarations: std::cell::RefCell<foliage::FunctionDeclarations>,
pub predicate_declarations: std::cell::RefCell<foliage::PredicateDeclarations>,
statements: std::cell::RefCell<std::collections::BTreeMap<SectionKind, Vec<Statement>>>,
pub input_constant_declarations: std::cell::RefCell<foliage::FunctionDeclarations>,
pub input_constant_declaration_domains:
std::cell::RefCell<crate::InputConstantDeclarationDomains>,
pub input_predicate_declarations: std::cell::RefCell<foliage::PredicateDeclarations>,
// TODO: clean up as variable declarations are dropped
variable_declaration_domains: std::cell::RefCell<VariableDeclarationDomains>,
}
impl Problem
{
pub fn new() -> Self
{
Self
{
function_declarations: std::cell::RefCell::new(foliage::FunctionDeclarations::new()),
predicate_declarations: std::cell::RefCell::new(foliage::PredicateDeclarations::new()),
statements: std::cell::RefCell::new(std::collections::BTreeMap::new()),
input_constant_declarations:
std::cell::RefCell::new(foliage::FunctionDeclarations::new()),
input_constant_declaration_domains:
std::cell::RefCell::new(crate::InputConstantDeclarationDomains::new()),
input_predicate_declarations:
std::cell::RefCell::new(foliage::PredicateDeclarations::new()),
variable_declaration_domains:
std::cell::RefCell::new(VariableDeclarationDomains::new()),
}
}
pub fn add_statement(&self, section_kind: SectionKind, statement: Statement)
{
let mut statements = self.statements.borrow_mut();
let section = statements.entry(section_kind).or_insert(vec![]);
section.push(statement);
}
pub fn prove(&self, proof_direction: crate::ProofDirection)
{
if proof_direction == crate::ProofDirection::Forward
|| proof_direction == crate::ProofDirection::Both
{
log::info!("performing forward proof");
let mut statements = self.statements.borrow_mut();
// Initially reset all proof statuses
for (_, statements) in statements.iter_mut()
{
for statement in statements.iter_mut()
{
match statement.kind
{
StatementKind::Axiom
| StatementKind::Assumption
=> statement.proof_status = ProofStatus::AssumedProven,
_ => statement.proof_status = ProofStatus::ToProve,
}
}
}
drop(statements);
self.prove_unproven_statements();
log::info!("finished forward proof");
}
if proof_direction == crate::ProofDirection::Backward
|| proof_direction == crate::ProofDirection::Both
{
log::info!("performing backward proof");
let mut statements = self.statements.borrow_mut();
// Initially reset all proof statuses
for (_, statements) in statements.iter_mut()
{
for statement in statements.iter_mut()
{
match statement.kind
{
StatementKind::Axiom
| StatementKind::Assertion
=> statement.proof_status = ProofStatus::AssumedProven,
_ => statement.proof_status = ProofStatus::ToProve,
}
}
}
drop(statements);
self.prove_unproven_statements();
log::info!("finished backward proof");
}
}
fn prove_unproven_statements(&self) -> Result<(), crate::Error>
{
while self.statements.borrow()
.iter()
.find(|section|
section.1.iter().find(|x| x.proof_status == ProofStatus::ToProve).is_some())
.is_some()
{
let mut tptp_problem_to_prove_next_statement = "".to_string();
self.write_tptp_problem_to_prove_next_statement(
&mut tptp_problem_to_prove_next_statement)
.map_err(|error| crate::Error::new_write_tptp_program(error))?;
log::info!("proving program:\n{}", &tptp_problem_to_prove_next_statement);
// TODO: refactor
let mut conjecture_found = false;
for section in self.statements.borrow_mut().iter_mut()
{
for statement in section.1.iter_mut()
{
if statement.proof_status == ProofStatus::ToProve
{
conjecture_found = true;
statement.proof_status = ProofStatus::AssumedProven;
}
if conjecture_found
{
break;
}
}
if conjecture_found
{
break;
}
}
log::info!("program proven!");
}
Ok(())
}
fn display(&self, output_format: crate::output::Format)
{
let format_context = FormatContext
{
program_variable_declaration_ids:
std::cell::RefCell::new(VariableDeclarationIDs::new()),
integer_variable_declaration_ids:
std::cell::RefCell::new(VariableDeclarationIDs::new()),
input_constant_declaration_domains: &self.input_constant_declaration_domains.borrow(),
variable_declaration_domains: &self.variable_declaration_domains.borrow(),
};
let print_title = |title, section_separator|
{
print!("{}{}", section_separator, "%".repeat(72));
print!("\n% {}", title);
println!("\n{}", "%".repeat(72));
};
let print_formula = |formula: &foliage::Formula|
{
match output_format
{
crate::output::Format::HumanReadable => print!("{}",
foliage::format::display_formula(formula, &format_context)),
crate::output::Format::TPTP => print!("{}",
crate::output::tptp::display_formula(formula, &format_context)),
}
};
let mut section_separator = "";
if output_format == crate::output::Format::TPTP
{
print_title("anthem types", section_separator);
section_separator = "\n";
let tptp_preamble_anthem_types
= include_str!("output/tptp/preamble_types.tptp").trim_end();
println!("{}", tptp_preamble_anthem_types);
print_title("anthem axioms", section_separator);
let tptp_preamble_anthem_types
= include_str!("output/tptp/preamble_axioms.tptp").trim_end();
println!("{}", tptp_preamble_anthem_types);
if !self.predicate_declarations.borrow().is_empty()
|| !self.function_declarations.borrow().is_empty()
{
print_title("types", section_separator);
if !self.predicate_declarations.borrow().is_empty()
{
println!("% predicate types")
}
for predicate_declaration in self.predicate_declarations.borrow().iter()
{
println!("tff(type, type, {}).",
crate::output::tptp::display_predicate_declaration(predicate_declaration));
}
if !self.function_declarations.borrow().is_empty()
{
println!("% function types")
}
for function_declaration in self.function_declarations.borrow().iter()
{
println!("tff(type, type, {}).",
crate::output::tptp::display_function_declaration(function_declaration,
&format_context));
}
}
let function_declarations = self.function_declarations.borrow();
let symbolic_constants = function_declarations.iter().filter(
|x| !self.input_constant_declaration_domains.borrow().contains_key(*x));
let mut last_symbolic_constant: Option<std::rc::Rc<foliage::FunctionDeclaration>> =
None;
for (i, symbolic_constant) in symbolic_constants.enumerate()
{
// Order axioms are only necessary with two or more symbolic constants
if i == 1
{
println!("% axioms for order of symbolic constants")
}
if symbolic_constant.arity > 0
{
// TODO: refactor
panic!("unexpected n-ary function declaration");
}
if let Some(last_symbolic_constant) = last_symbolic_constant
{
println!("tff(symbolic_constant_order, axiom, p__less__({}, {})).",
last_symbolic_constant.name, symbolic_constant.name);
}
last_symbolic_constant = Some(std::rc::Rc::clone(symbolic_constant));
}
}
for (section_kind, statements) in self.statements.borrow().iter()
{
if statements.is_empty()
{
continue;
}
let title = match section_kind
{
SectionKind::CompletedDefinitions => "completed definitions",
SectionKind::IntegrityConstraints => "integrity constraints",
SectionKind::Axioms => "axioms",
SectionKind::Assumptions => "assumptions",
SectionKind::Lemmas => "lemmas",
SectionKind::Assertions => "assertions",
};
print_title(title, section_separator);
section_separator = "\n";
let mut i = 0;
for statement in statements.iter()
{
if let Some(ref description) = statement.description
{
println!("% {}", description);
}
let name = match &statement.name
{
// TODO: refactor
Some(name) => name.clone(),
None =>
{
i += 1;
format!("statement_{}", i)
},
};
if output_format == crate::output::Format::TPTP
{
// TODO: add proper statement type
print!("tff({}, axiom, ", name);
}
print_formula(&statement.formula);
if output_format == crate::output::Format::TPTP
{
print!(").");
}
println!("");
}
}
}
fn write_tptp_problem_to_prove_next_statement(&self, formatter: &mut String) -> std::fmt::Result
{
use std::fmt::Write as _;
use std::io::Write as _;
let format_context = FormatContext
{
program_variable_declaration_ids:
std::cell::RefCell::new(VariableDeclarationIDs::new()),
integer_variable_declaration_ids:
std::cell::RefCell::new(VariableDeclarationIDs::new()),
input_constant_declaration_domains: &self.input_constant_declaration_domains.borrow(),
variable_declaration_domains: &self.variable_declaration_domains.borrow(),
};
let write_title = |formatter: &mut String, title, section_separator| -> std::fmt::Result
{
write!(formatter, "{}{}", section_separator, "%".repeat(72))?;
write!(formatter, "\n% {}", title)?;
writeln!(formatter, "\n{}", "%".repeat(72))
};
let mut section_separator = "";
write_title(formatter, "anthem types", section_separator)?;
section_separator = "\n";
let tptp_preamble_anthem_types
= include_str!("output/tptp/preamble_types.tptp").trim_end();
writeln!(formatter, "{}", tptp_preamble_anthem_types)?;
write_title(formatter, "anthem axioms", section_separator)?;
let tptp_preamble_anthem_types
= include_str!("output/tptp/preamble_axioms.tptp").trim_end();
writeln!(formatter, "{}", tptp_preamble_anthem_types)?;
if !self.predicate_declarations.borrow().is_empty()
|| !self.function_declarations.borrow().is_empty()
{
write_title(formatter, "types", section_separator)?;
if !self.predicate_declarations.borrow().is_empty()
{
writeln!(formatter, "% predicate types")?;
}
for predicate_declaration in self.predicate_declarations.borrow().iter()
{
writeln!(formatter, "tff(type, type, {}).",
crate::output::tptp::display_predicate_declaration(predicate_declaration))?;
}
if !self.function_declarations.borrow().is_empty()
{
writeln!(formatter, "% function types")?;
}
for function_declaration in self.function_declarations.borrow().iter()
{
writeln!(formatter, "tff(type, type, {}).",
crate::output::tptp::display_function_declaration(function_declaration,
&format_context))?;
}
}
let function_declarations = self.function_declarations.borrow();
let symbolic_constants = function_declarations.iter().filter(
|x| !self.input_constant_declaration_domains.borrow().contains_key(*x));
let mut last_symbolic_constant: Option<std::rc::Rc<foliage::FunctionDeclaration>> =
None;
for (i, symbolic_constant) in symbolic_constants.enumerate()
{
// Order axioms are only necessary with two or more symbolic constants
if i == 1
{
writeln!(formatter, "% axioms for order of symbolic constants")?;
}
if symbolic_constant.arity > 0
{
// TODO: refactor
unimplemented!("n-ary function declarations arent supported");
}
if let Some(last_symbolic_constant) = last_symbolic_constant
{
writeln!(formatter, "tff(symbolic_constant_order, axiom, p__less__({}, {})).",
last_symbolic_constant.name, symbolic_constant.name)?;
}
last_symbolic_constant = Some(std::rc::Rc::clone(symbolic_constant));
}
let mut conjecture_found = false;
for (section_kind, statements) in self.statements.borrow().iter()
{
if statements.is_empty()
{
continue;
}
let title = match section_kind
{
SectionKind::CompletedDefinitions => "completed definitions",
SectionKind::IntegrityConstraints => "integrity constraints",
SectionKind::Axioms => "axioms",
SectionKind::Assumptions => "assumptions",
SectionKind::Lemmas => "lemmas",
SectionKind::Assertions => "assertions",
};
write_title(formatter, title, section_separator)?;
section_separator = "\n";
let mut i = 0;
for statement in statements.iter()
{
// Only prove one statement at a time
if conjecture_found && statement.proof_status == ProofStatus::ToProve
{
continue;
}
if let Some(ref description) = statement.description
{
writeln!(formatter, "% {}", description)?;
}
let name = match &statement.name
{
// TODO: refactor
Some(name) => name.clone(),
None =>
{
i += 1;
format!("statement_{}", i)
},
};
let statement_type = match statement.proof_status
{
ProofStatus::AssumedProven => "axiom",
ProofStatus::ToProve =>
{
conjecture_found = true;
"conjecture"
},
};
// TODO: add proper statement type
writeln!(formatter, "tff({}, {}, {}).", name, statement_type,
crate::output::tptp::display_formula(&statement.formula, &format_context))?;
}
}
Ok(())
}
}
impl foliage::FindOrCreateFunctionDeclaration for Problem
{
fn find_or_create_function_declaration(&self, name: &str, arity: usize)
-> std::rc::Rc<foliage::FunctionDeclaration>
{
let mut function_declarations = self.function_declarations.borrow_mut();
match function_declarations.iter().find(|x| x.name == name && x.arity == arity)
{
Some(declaration) => std::rc::Rc::clone(&declaration),
None =>
{
let declaration = foliage::FunctionDeclaration
{
name: name.to_string(),
arity,
};
let declaration = std::rc::Rc::new(declaration);
function_declarations.insert(std::rc::Rc::clone(&declaration));
log::debug!("new function declaration: {}/{}", name, arity);
declaration
},
}
}
}
impl foliage::FindOrCreatePredicateDeclaration for Problem
{
fn find_or_create_predicate_declaration(&self, name: &str, arity: usize)
-> std::rc::Rc<foliage::PredicateDeclaration>
{
let mut predicate_declarations = self.predicate_declarations.borrow_mut();
match predicate_declarations.iter().find(|x| x.name == name && x.arity == arity)
{
Some(declaration) => std::rc::Rc::clone(&declaration),
None =>
{
let declaration = foliage::PredicateDeclaration
{
name: name.to_string(),
arity,
};
let declaration = std::rc::Rc::new(declaration);
predicate_declarations.insert(std::rc::Rc::clone(&declaration));
log::debug!("new predicate declaration: {}/{}", name, arity);
declaration
},
}
}
}
impl crate::traits::AssignVariableDeclarationDomain for Problem
{
fn assign_variable_declaration_domain(&self,
variable_declaration: &std::rc::Rc<foliage::VariableDeclaration>, domain: crate::Domain)
{
let mut variable_declaration_domains = self.variable_declaration_domains.borrow_mut();
match variable_declaration_domains.get(variable_declaration)
{
Some(current_domain) => assert_eq!(*current_domain, domain,
"inconsistent variable declaration domain"),
None =>
{
variable_declaration_domains
.insert(std::rc::Rc::clone(variable_declaration).into(), domain);
},
}
}
}
impl<'a, 'b> FormatContext<'a, 'b>
{
fn variable_declaration_id(&self,
variable_declaration: &std::rc::Rc<foliage::VariableDeclaration>)
-> usize
{
let mut variable_declaration_ids = match self.variable_declaration_domains
.get(variable_declaration)
{
Some(crate::Domain::Program) => self.program_variable_declaration_ids.borrow_mut(),
Some(crate::Domain::Integer) => self.integer_variable_declaration_ids.borrow_mut(),
None => unreachable!("all variables should be declared at this point"),
};
match variable_declaration_ids.get(variable_declaration)
{
Some(id) => *id,
None =>
{
let id = variable_declaration_ids.len();
variable_declaration_ids.insert(std::rc::Rc::clone(variable_declaration).into(), id);
id
},
}
}
}
impl<'a, 'b> crate::traits::InputConstantDeclarationDomain for FormatContext<'a, 'b>
{
fn input_constant_declaration_domain(&self,
declaration: &std::rc::Rc<foliage::FunctionDeclaration>) -> crate::Domain
{
// Assume the program domain if not specified otherwise
self.input_constant_declaration_domains.get(declaration).map(|x| *x)
.unwrap_or(crate::Domain::Program)
}
}
impl<'a, 'b> crate::traits::VariableDeclarationDomain for FormatContext<'a, 'b>
{
fn variable_declaration_domain(&self,
variable_declaration: &std::rc::Rc<foliage::VariableDeclaration>)
-> Option<crate::Domain>
{
self.variable_declaration_domains.get(variable_declaration)
.map(|x| *x)
}
}
impl<'a, 'b> crate::traits::VariableDeclarationID for FormatContext<'a, 'b>
{
fn variable_declaration_id(&self,
variable_declaration: &std::rc::Rc<foliage::VariableDeclaration>)
-> usize
{
use crate::traits::VariableDeclarationDomain;
let mut variable_declaration_ids = match self.variable_declaration_domain(
variable_declaration)
{
Some(crate::Domain::Program) => self.program_variable_declaration_ids.borrow_mut(),
Some(crate::Domain::Integer) => self.integer_variable_declaration_ids.borrow_mut(),
None => panic!("all variables should be declared at this point"),
};
match variable_declaration_ids.get(variable_declaration)
{
Some(id) =>
{
*id
}
None =>
{
let id = variable_declaration_ids.len();
variable_declaration_ids.insert(std::rc::Rc::clone(variable_declaration).into(), id);
id
},
}
}
}
impl<'a, 'b> foliage::format::Format for FormatContext<'a, 'b>
{
fn display_variable_declaration(&self, formatter: &mut std::fmt::Formatter,
variable_declaration: &std::rc::Rc<foliage::VariableDeclaration>)
-> std::fmt::Result
{
let id = self.variable_declaration_id(variable_declaration);
let domain = self.variable_declaration_domains.get(variable_declaration)
.expect("unspecified variable domain");
let prefix = match domain
{
crate::Domain::Integer => "N",
crate::Domain::Program => "X",
};
write!(formatter, "{}{}", prefix, id + 1)
}
}