1. 20 Jan, 2014 6 commits
    • Andrei Paskevich's avatar
      minor English grammar fix · dff7079b
      Andrei Paskevich authored
      dff7079b
    • Andrei Paskevich's avatar
      update a session · 8ac1e905
      Andrei Paskevich authored
      8ac1e905
    • Andrei Paskevich's avatar
      "eliminate_epsilon" added in drivers · 9c20cd7c
      Andrei Paskevich authored
      Currently, the builtin theory why3.HighOrd (or just HighOrd) must
      be explicitly "use"-d. However, the type (HighOrd.func 'a 'b) can
      be written ('a -> 'b), and the type (HighOrd.pred 'a) can be written
      ('a -> bool), and the application operation (HighOrd.(@)) can be
      written as the usual juxtaposition. Thus, normally, you do not have
      to write the qualifiers. The builtin theory why3.Bool (or just Bool)
      is needed for "bool". The names "HighOrd", "func", "pred", and "(@)"
      are not yet fixed and may change.
      
      "eliminate_epsilon" tries to be smart when a lambda (or some other
      comprehension form) occurs under equality or at the top of a definition.
      We could go even further and replace (\ x . t) s with t[x <- s], without
      lifting the lambda. I'm not sure it's worth it: we rarely write redexes
      manually. They can and will appear through inlining, though.
      
      Anyone who wants to construct epsilon-terms directly using the API
      should remember that these are not Hilbert's epsilons: by writing
      an epsilon term, you postulate the existence (though not necessarily
      uniqueness) of the described object, and "eliminate_epsilon" will
      happily convert it to an axiom expressing this existence. We only
      use epsilons to write comprehensions whose soundness is guaranteed
      by a background theory, e.g. lambda-calculus.
      9c20cd7c
    • Andrei Paskevich's avatar
      restore lost proofs in sessions · a8b30bac
      Andrei Paskevich authored
      a8b30bac
    • Andrei Paskevich's avatar
    • Andrei Paskevich's avatar
      WhyML: add "diverges", "reads {}", and "writes {}" effect clauses · 83858597
      Andrei Paskevich authored
      - "diverges" states that the computation may not terminate (which
        does not mean that is always diverges: just as any other effect
        annotation, this clause states a possibility of a side effect).
      
      - "reads {}" states that the computation does not access any variable
        except those that are listed elsewhere in the specification (or the
        proper function arguments, if "reads" is in a function spec).
      
      - "writes {}" states that the computation does not modify any mutable
        value.
      
      - If a function definition or an abstract computation may diverge,
        but there is no "diverges" clause in the specification, a warning
        is produced. If a function definition or an abstract computation
        always terminates, but there is a "diverges" clause in the spec,
        an error is produced.
      
      - If there is a "reads" or a "writes" clause in a function definition
        or an abstract computation, then every modified value must be listed
        in "writes" and every accessed external variable not mentioned in
        the spec must be listed in "reads". (Notice that this is a stricter
        requirement than before, when the presence of a "writes" clause
        did not require to specify "reads".) However, one does not have to
        write "reads {}" or "writes {}" if the corresponding lists are empty.
      83858597
  2. 19 Jan, 2014 9 commits
  3. 18 Jan, 2014 3 commits
  4. 17 Jan, 2014 1 commit
  5. 16 Jan, 2014 5 commits
  6. 15 Jan, 2014 3 commits
  7. 14 Jan, 2014 9 commits
  8. 13 Jan, 2014 1 commit
  9. 12 Jan, 2014 1 commit
  10. 09 Jan, 2014 1 commit
  11. 08 Jan, 2014 1 commit