jitterbug serval

modelling the heap

why3 implemtnation of stackify Stackifty algorithm of llvm for wasm

Why is structuring unstructured control flow so important?

Weakest-precondition of unstructured programs banrett leino what can you do with an isa spec - alastair reid

Imp stmt to stack machine Imp expr to stack machine

Expr as state? Expr + Context as state. Ok sure. List stack as state Try just binary operator Try booleans rather than nats

There is a single reflection step to a machine

forall s1 : S1, s2 : S2, (p : s1 ~ s2), (R1 s1 s1’) (R2 s2 s2’) : s1’ ~ s2’

Maybe verifying a pipelined processor (how hard could it be amirite?!?!) would be a fun concurrency example to attempt int ivy or tla+ or whatever instruction semantics for x86 in K Synthesiszing automatically learning semantics of x86

The Hamming Book. Gilbert Strang book. Numerical analysis Geometrical algorithms Stuff in CLRS?

limbs circuit. 3d printed snapping.

Use z3-wasm.

Specit - word based specification challenges. Prove equivalence using Z3?

let’s as assignemnt injecting block addigment variables after phi nodes gated ssa vs

smtlib preporcoesor - wp mode.

boogie why

Different styles of proving on CFGs.

The CFG is already giving you a lot, to pretend you know what jumps are possible. This does let you

Nand2Tetris style, we could model the gates of the hardware. And then unfold in time using BMC

  • Do we maintain the instruction pointer as a concept?
  • For every block, with every entrance and exit, one could manually state a summary entrance and summary exit predciates. For every edge linking an exit to and entrance one requires that P - Q. And in addition that the entrance predicates imply the exit predicates of the block itself
  • DAGs present no problems as CFGs. You can finitely produce a trasntiion relation for them, or run WP on them. So one perspective if that you need to cut enough edges to make the cfg a dag. And every time you cut an edge, you need a predicate associated with that edge or perhaps one with the entrance and one with the exit of that edge.
  • Lamport had some mention of ther Floyd method as being more general than the hoare method. Floyd seemed to be considering cfgs. TLA+ does explicitly model the program counter.
  • Symbolic execution branches at the logical level instead of at the logical level. This does not lend itself obviously to something that works in the presence of loops.

We could do the Micro-WP to demonstrate these styles. But it is a pain. Infer a CFG for Nand2Tetris? Perhaps hards because it can be difficult to know what locations you may jump to. We could instead work in a CFG intermediate representation that compiles.

class Block: code: list[instr] # no jumps jump: A1, A2, JMP

Fuzzing is so fuckin useful. To not beusing dynamic techniques afl fuzzing training afl++ qemy libfuzzer vs afl vs honggfuzz corpus grammar based fuzzing, differential fuzzing

What changes do yoiu need to make to use arbitrary control flow graphs vs structured programs Rustan leino book

Djikstra monads - this might be a stretch F* Djikstra moand + interaciton trees Interaction trees ~ free monad rearranged for total language related to freer monads - kiselyov thing. This is what lexi king was working on yea?

General Monad mcbride from C to interaction trees li-yao xia

Disjkstra and Scholten That link off of Leino

Could I make an equation style system in Z3py? Probably, right? Take Agda as an example Backhouse Hehner

I’ve been feeling like i should be doing manual hoare logic/ imperative proofs

There is a vast assortment of tools out there that aren’t proof assistants.

Boogie, dafny, frama-c, viper, verifast, whyml, why3, liquidhaskell, spark/ada, spec# JML, ESC/java whiley esc/modula-3

dafny vs code plugin

viper vs code plugin


verifast tutorial vcc ZetZZ dafny discussion Verilog + symbiyosys, KeY, KeymaeraX CBMC, ESBMC , EBMC cpa-checker TLA might be in this category Event-B alloy god this list is nuts verify this sv-comp

Eiffel for pre post conditions chalice ATS

F*, Iris, VST, Bedrock Isabelle?

It’s interesting that logical psecs are so foreign, and somewhat longwinded when applied to imperative code, that they aren’t that much more understandable or high assurance. Really it might be about formally proving equaivlance between just specs in different languages. Python and C for example.

A good question is: what are interesting programs to prove?

  1. List manipulation
  2. sorts
  3. red black trees
  4. find

Fun old timey books.

If you go before 1980, a decent chunk of all books had assembly in mind.

  • discpline of programming - djikstra
  • Reynolds - The craft of programming
  • Knuth - The Art of Computer Programming
  • The science of programming - D Gries
  • Pascal, wirth
  • structured programming djikstra hoare
  • Eric Hehner
  • ACM classic books
  • lambda papers
  • per brinch hansen
  • some welevant EQD notes. Derivation of alogrithms
  • winskel