Finish basic simplifications

src/commands/verify_program.rs

@@ -1,5 +1,5 @@
-pub fn run<P>(program_path: P, specification_path: P, proof_direction:
-	crate::problem::ProofDirection)
+pub fn run<P>(program_path: P, specification_path: P,
+	proof_direction: crate::problem::ProofDirection, no_simplify: bool)
 where
 	P: AsRef<std::path::Path>,
 {
@@ -60,6 +60,19 @@ where
 		}
 	}
 
+	if !no_simplify
+	{
+		match problem.simplify()
+		{
+			Ok(_) => (),
+			Err(error) =>
+			{
+				log::error!("could not simplify translated program: {}", error);
+				std::process::exit(1)
+			}
+		}
+	}
+
 	match problem.prove(proof_direction)
 	{
 		Ok(()) => (),

src/main.rs

@@ -19,6 +19,10 @@ enum Command
 		/// Proof direction (forward, backward, both)
 		#[structopt(long, default_value = "forward")]
 		proof_direction: anthem::problem::ProofDirection,
+
+		/// Do not simplify translated program
+		#[structopt(long)]
+		no_simplify: bool,
 	}
 }
 
@@ -35,8 +39,9 @@ fn main()
 			program_path,
 			specification_path,
 			proof_direction,
+			no_simplify,
 		}
 			=> anthem::commands::verify_program::run(&program_path, &specification_path,
-				proof_direction),
+				proof_direction, no_simplify),
 	}
 }

src/problem.rs

@@ -44,7 +44,7 @@ impl Problem
 		}
 	}
 
-	pub(crate) fn add_statement(&self, section_kind: SectionKind, mut statement: Statement)
+	pub(crate) 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![]);
@@ -151,6 +151,28 @@ impl Problem
 		Ok(())
 	}
 
+	pub fn simplify(&mut self) -> Result<(), crate::Error>
+	{
+		let mut statements = self.statements.borrow_mut();
+
+		for (_, statements) in statements.iter_mut()
+		{
+			for statement in statements.iter_mut()
+			{
+				match statement.kind
+				{
+					// Only simplify generated formulas
+					| StatementKind::CompletedDefinition(_)
+					| StatementKind::IntegrityConstraint =>
+						crate::simplify(&mut statement.formula)?,
+					_ => (),
+				}
+			}
+		}
+
+		Ok(())
+	}
+
 	fn print_step_title(&self, step_title: &str, color: &termcolor::ColorSpec)
 		-> Result<(), crate::Error>
 	{
@@ -319,13 +341,8 @@ impl Problem
 			self.shell.borrow_mut().print(&format!("{}: ", statement.kind),
 				&termcolor::ColorSpec::new())?;
 
-			match statement.kind
-			{
-				StatementKind::CompletedDefinition(_)
-				| StatementKind::IntegrityConstraint =>
-					crate::autoname_variables(&mut statement.formula),
-				_ => (),
-			}
+			// TODO: only perform autonaming when necessary
+			crate::autoname_variables(&mut statement.formula);
 
 			print!("{}", statement.formula);
 

src/simplify.rs

@@ -18,9 +18,10 @@ impl SimplificationResult
 	}
 }
 
-fn remove_unnecessary_exists_parameters(formula: &mut crate::Formula) -> SimplificationResult
+fn remove_unnecessary_exists_parameters(formula: &mut crate::Formula)
+	-> Result<SimplificationResult, crate::Error>
 {
-	use crate::Formula;
+	use crate::{Formula, Term};
 
 	match formula
 	{
@@ -33,18 +34,18 @@ fn remove_unnecessary_exists_parameters(formula: &mut crate::Formula) -> Simplif
 			for argument in arguments
 			{
 				simplification_result = simplification_result.or(
-					remove_unnecessary_exists_parameters(argument));
+					remove_unnecessary_exists_parameters(argument)?);
 			}
 
-			simplification_result
+			Ok(simplification_result)
 		},
 		Formula::Boolean(_)
 		| Formula::Compare(_)
-		| Formula::Predicate(_) => SimplificationResult::NotSimplified,
+		| Formula::Predicate(_) => Ok(SimplificationResult::NotSimplified),
 		Formula::Exists(ref mut quantified_formula) =>
 		{
 			let mut simplification_result =
-				remove_unnecessary_exists_parameters(&mut quantified_formula.argument);
+				remove_unnecessary_exists_parameters(&mut quantified_formula.argument)?;
 
 			let arguments = match *quantified_formula.argument
 			{
@@ -69,31 +70,55 @@ fn remove_unnecessary_exists_parameters(formula: &mut crate::Formula) -> Simplif
 									_ => return None,
 								};
 
-								if let foliage::Term::Variable(ref variable) = **left
+								let assigned_term = match (&**left, &**right)
 								{
-									if variable.declaration == *parameter
-										&& !crate::term_contains_variable(right, parameter)
+									(Term::Variable(ref variable), right)
+										if variable.declaration == *parameter =>
+										right,
+									(left, Term::Variable(ref variable))
+										if variable.declaration == *parameter =>
+										left,
+									_ => return None,
+								};
+
+								let parameter_domain = match parameter.domain()
+								{
+									Ok(domain) => domain,
+									Err(_) =>
+										unreachable!("all variable domains should be assigned at this point"),
+								};
+
+								let is_parameter_integer =
+									parameter_domain == crate::Domain::Integer;
+
+								let is_assigned_term_arithmetic =
+									match crate::is_term_arithmetic(assigned_term)
 									{
-										// TODO: avoid copy
-										return Some((argument_index, crate::copy_term(right)));
-									}
+										Ok(is_term_arithmetic) => is_term_arithmetic,
+										Err(error) => return Some(Err(error)),
+									};
+
+								let is_assignment_narrowing = is_parameter_integer
+									&& !is_assigned_term_arithmetic;
+
+								if crate::term_contains_variable(assigned_term, parameter)
+									|| is_assignment_narrowing
+								{
+									return None;
 								}
 
-								if let foliage::Term::Variable(ref variable) = **right
-								{
-									if variable.declaration == *parameter
-										&& !crate::term_contains_variable(left, parameter)
-									{
-										// TODO: avoid copy
-										return Some((argument_index, crate::copy_term(left)));
-									}
-								}
-
-								None
+								// TODO: avoid copy
+								Some(Ok((argument_index, crate::copy_term(assigned_term))))
 							});
 
-						if let Some((assignment_index, assigned_term)) = assignment
+						if let Some(assignment) = assignment
 						{
+							let (assignment_index, assigned_term) = match assignment
+							{
+								Err(error) => return Some(Err(error)),
+								Ok(assignment) => assignment,
+							};
+
 							arguments.remove(assignment_index);
 
 							for argument in arguments.iter_mut()
@@ -107,11 +132,11 @@ fn remove_unnecessary_exists_parameters(formula: &mut crate::Formula) -> Simplif
 							return None;
 						}
 
-						Some(std::rc::Rc::clone(parameter))
+						Some(Ok(std::rc::Rc::clone(parameter)))
 					})
-					.collect());
+					.collect::<Result<_, _>>()?);
 
-			simplification_result
+			Ok(simplification_result)
 		}
 		Formula::ForAll(ref mut quantified_formula) =>
 			remove_unnecessary_exists_parameters(&mut quantified_formula.argument),
@@ -225,22 +250,20 @@ fn simplify_trivial_n_ary_formulas(formula: &mut crate::Formula) -> Simplificati
 	}
 }
 
-pub(crate) fn simplify(formula: &mut crate::Formula)
+pub(crate) fn simplify(formula: &mut crate::Formula) -> Result<(), crate::Error>
 {
 	loop
 	{
-		if remove_unnecessary_exists_parameters(formula) == SimplificationResult::Simplified
+		if remove_unnecessary_exists_parameters(formula)? == SimplificationResult::Simplified
 			|| simplify_quantified_formulas_without_parameters(formula)
 				== SimplificationResult::Simplified
 			|| simplify_trivial_n_ary_formulas(formula) == SimplificationResult::Simplified
 		{
-			log::debug!("cool, simplified!");
-
 			continue;
 		}
 
-		log::debug!("nope, that’s it");
-
 		break;
 	}
+
+	Ok(())
 }

src/translate/verify_properties.rs

@@ -146,11 +146,9 @@ impl<'p> Translator<'p>
 			let statement_kind = crate::problem::StatementKind::CompletedDefinition(
 				std::rc::Rc::clone(&predicate_declaration));
 
-			let mut completed_definition = completed_definition(predicate_declaration,
+			let completed_definition = completed_definition(predicate_declaration,
 				&mut self.definitions);
 
-			//crate::simplify(&mut completed_definition);
-
 			let statement_name =
 				format!("completed_definition_{}", predicate_declaration.tptp_statement_name());
 
@@ -287,8 +285,6 @@ impl<'p> Translator<'p>
 
 				let integrity_constraint = crate::universal_closure(open_formula);
 
-				//crate::simplify(&mut integrity_constraint);
-
 				let statement = crate::problem::Statement::new(
 					crate::problem::StatementKind::IntegrityConstraint, integrity_constraint)
 					.with_name("integrity_constraint".to_string());