Applied Formal Methods

AERE/COMS 407/507
Applied Formal Methods

Course Summary

In this course you will be introduced to best practices for the application of formal methods, a set of mathematically rigourous techniques for the formal specification, validation, and verification of safety- and security-critical cyberphysical systems, of which aircraft and spacecraft are the prime example. We will explore the tools, techniques, and applications of formal methods, focusing on the aerospace domain. We will examine the latest research to gain an understanding of the current state of the art, including the capabilities and limitations of applying formal methods for systems analysis. Students will leave with a better understanding of real-world system specification, design, and verification, including why the FAA specifically calls out formal methods in certification requirements such as DO-178B, DO-178C, and DO-254, and why modern security teams from DARPA to AWS require formal methods for cloud security.

This course is intended to be a fun, interactive introduction to applying formal analysis in the context of real-world systems. Hands-on learning, through the use of software tools in homeworks and projects, will be emphasized. We will learn the real tools used at NASA, Boeing, Collins Aerospace, Honeywell, Airbus, Amazon, and others. Students from all areas of aerospace engineering, electrical and computer engineering, computer science, cybersecurity, mathematics, and other engineering disciplines, are encouraged to enroll. It is registered in the international FME Education Course Database.

Course Syllabus

Prerequisites

The prerequisite is mathematical maturity: Calculus II plus familiarity with discrete mathematics (or ability to learn them quickly from review material made available in the course). This prerequisite take the form of a disjunction; one of the following is required: AERE 361, COMS 311, or permission of the instructor (e.g., for students in other departments). Registering for 407 always requires instructor permission.

Tools

	Spin Model Checker http://spinroot.com/ Books: http://spinroot.com/spin/books.html
	SPOT Produces Our Traces https://spot.lrde.epita.fr/ More generally, JFLAP simulates automata
	nuXmv Model Checker https://es-static.fbk.eu/tools/nuxmv/ In addition to the manuals, see the Introduction Slides
	Isabelle Theorem Prover https://isabelle.in.tum.de/ Also: The Isabelle Cookbook and Guide for Beginners; See also Linear Temporal Logic, and Propositional and Modal Logic in Isabelle (also Modal Logics for Nominal Transition Systems), and Hybrid Logics like Epistemic Logic, State Counting/Reduction
	PVS Theorem Prover http://pvs.csl.sri.com/ NASA PVS Library (NASALib) v7.1 (https://github.com/nasa/pvslib) NASA PVS VSCode GUI (https://github.com/nasa/vscode-pvs) 30+ years of theorem proving at NASA: https://shemesh.larc.nasa.gov/fm/pvs/
	PRISM Model Checker http://www.prismmodelchecker.org/
	Responsive Realizable Unobtrusive Unit (R2U2) http://temporallogic.org/research/R2U2/
	Dafny Language and Program Verifier http://rise4fun.com/dafny/ https://github.com/dafny-lang/dafny Note that Dafny has many popular video tutorials!
	Z3 SMT Solver https://github.com/Z3Prover/z3 See also: SMT: Something You Must Try
	CBMC (Bounded Model Checker for C programs) http://www.cprover.org/cbmc/ Tip: CBMC has little support for C++; use for C only. Use CBMC for "unit proof" starting from the leaves of the call tree and working toward the root call; see Amazon's strategy here: https://nchong.github.io/papers/icse-seip20.pdf
	Coq Proof Assistant https://coq.inria.fr/ Book: Formal Reasoning About Programs

	Software Model Checking Competition on Software Verification (SV-COMP)
	Hardware Model Checking HardWare Model Checking Competition (HWMCC)
	Static Analysis Static Analysis: An Introduction
	ATP (Automated Theorem Proving) The CADE ATP System Competition: The World Championship for Automated Theorem Proving

Do not struggle with tool installation on your own machine! If you are running linux, these tools should all install easily, but if not, use the provided virtal machines. There is no credit for time spent trying to install a tool. To access tools like spin, you will need to vpn in from off campus and then ssh -X username@aere407.ece.iastate.edu. This works from a command line (e.g., in linux), or from mobaXterm in windows. All software (e.g., Isabelle and nuXmv) is installed in /usr/local/packagename, except for spin and ispin, which are in /usr/local/bin. The GUI ispin is invoked by running "ispin.tcl" from the command line. Elizabeth Sloan wrote excellent advice for installing spin. Nathan Vaughn also wrote a blog post about how to get ispin working with windows. Zili Wang wrote excellent advice for installing Isabelle. If you insist on running a formal methods tool in an operating system that is not linux, you can try using this fm-weck formal methods tool container; do this at your own risk!

Exam Dates (estimated)

Midterm: 10/24

Final Project: (in lieu of final exam)

Project Requirements:	HERE
Final Project GitHub classroom link:	HERE
Project Proposal:	10/24
Project Midterm Report:	11/11 or 11/18 Give short mid-term presentations on this day!
Project Presentations:	12/8: 12/11: 12/17:
Friday Progress Reports Due:	10/31, 11/7, 11/14, 11/21, 11/28 (optional), 12/5, 12/12
Final Report:	During exam period (9:45am-11:45am on Wednesday, 12/17)

Assignment Deadlines

Homework 0 due 8/28

Homework 1 due 9/4

Homework 2 due 9/16

Homework 3 due 10/2

Homework 4 due 10/14

Homework 5 due 10/23

Choice of research paper for in-class presentation due 10/21

Reading/Homeworks

Homework 0 (Review of Version Control and LaTeX primer): distributed 8/26 from CANVAS

Note: if you want a deeper understanding of git, there are many online courses.

Homework 1 (Propositional Logic Review): distributed 8/28 from CANVAS

Here is a handy condensed list of definitions here.

Homework 2 (Temporal Logic): distributed 8/30 from CANVAS

Homework 3: distributed 9/11 from CANVAS

Homework 4: distributed 10/2. Submit CANVAS

Proving Theorems With Computers

Homework 5: distributed 10/14 CANVAS

Choice of research paper for presention due via email: 10/21
You may not choose a paper authored by the professor.

Professor evaluation form for in-class presentations is available HERE
Student evaluation form for in-class presentations is available HERE

Here is some great advice on How to Give a Good Research Presentation.

Here is some great advice on How to Read a Paper (there is also advice on how to write papers and how to peer review papers).

Paper Presentation Schedule:
Each presentation should be approximately 30 minutes, including time for questions.

10/23	Midterm Examination
10/28	&
10/30	&
11/ 4	&
11/ 6	&
11/11	Midterm project report presentations
11/13	Midterm project report presentations
11/18	&
11/20	&
12/ 2	&
12/ 4	&
12/ 9	Final project report presentations
12/11	Final project report presentations
12/17	(during final exam period) Final project report presentations

Optional Textbooks

Use this for:

good background on LTL: well-formed formulas, semantics, encoding English sentences, expressivity, normal forms, relationship to automata
reactive system properties: safety, liveness, fairness
specification and modeling of real systems
deciding the truth of a temporal formula; related proof techniques including explicit model checking
thorough chapter on Spin, including how to run it from the command line and a good Promela tutorial
review of classical and propositional logic
extensions including synthesizing software from specifications

Be cautious that:

LTL is instead called PTL in this book; that is non-standard
LTL2BA is not the best tool; SPOT is far superior now: https://spot.lrde.epita.fr/
URLs provided are outdated (no longer active or superseded by the state of the art)
Spin chapter refers to outdated xspin (though only briefly)