diff --git a/src/Doc/Sledgehammer/document/root.tex b/src/Doc/Sledgehammer/document/root.tex --- a/src/Doc/Sledgehammer/document/root.tex +++ b/src/Doc/Sledgehammer/document/root.tex @@ -1,1362 +1,1360 @@ \documentclass[a4paper,12pt]{article} \usepackage[T1]{fontenc} \usepackage{amsmath} \usepackage{amssymb} \usepackage[english]{babel} \usepackage{color} \usepackage{footmisc} \usepackage{graphicx} %\usepackage{mathpazo} \usepackage{multicol} \usepackage{stmaryrd} %\usepackage[scaled=.85]{beramono} \usepackage{isabelle,iman,pdfsetup} \newcommand\download{\url{https://isabelle.in.tum.de/components/}} \let\oldS=\S \def\S{\oldS\,} \def\qty#1{\ensuremath{\left<\mathit{#1\/}\right>}} \def\qtybf#1{$\mathbf{\left<\textbf{\textit{#1\/}}\right>}$} \newcommand\const[1]{\textsf{#1}} %\oddsidemargin=4.6mm %\evensidemargin=4.6mm %\textwidth=150mm %\topmargin=4.6mm %\headheight=0mm %\headsep=0mm %\textheight=234mm \def\Colon{\mathord{:\mkern-1.5mu:}} %\def\lbrakk{\mathopen{\lbrack\mkern-3.25mu\lbrack}} %\def\rbrakk{\mathclose{\rbrack\mkern-3.255mu\rbrack}} \def\lparr{\mathopen{(\mkern-4mu\mid}} \def\rparr{\mathclose{\mid\mkern-4mu)}} \def\unk{{?}} \def\undef{(\lambda x.\; \unk)} %\def\unr{\textit{others}} \def\unr{\ldots} \def\Abs#1{\hbox{\rm{\flqq}}{\,#1\,}\hbox{\rm{\frqq}}} \def\Q{{\smash{\lower.2ex\hbox{$\scriptstyle?$}}}} \urlstyle{tt} \renewcommand\_{\hbox{\textunderscore\kern-.05ex}} \begin{document} %%% TYPESETTING %\renewcommand\labelitemi{$\bullet$} \renewcommand\labelitemi{\raise.065ex\hbox{\small\textbullet}} \title{\includegraphics[scale=0.5]{isabelle_sledgehammer} \\[4ex] Hammering Away \\[\smallskipamount] \Large A User's Guide to Sledgehammer for Isabelle/HOL} \author{\hbox{} \\ Jasmin Blanchette \\ {\normalsize Institut f\"ur Informatik, Technische Universit\"at M\"unchen} \\[4\smallskipamount] {\normalsize with contributions from} \\[4\smallskipamount] Martin Desharnais \\ {\normalsize Forschungsinstitut CODE, Universit\"at der Bundeswehr M\"unchen} \\[4\smallskipamount] Lawrence C. Paulson \\ {\normalsize Computer Laboratory, University of Cambridge} \\ \hbox{}} \maketitle \tableofcontents \setlength{\parskip}{.7em plus .2em minus .1em} \setlength{\parindent}{0pt} \setlength{\abovedisplayskip}{\parskip} \setlength{\abovedisplayshortskip}{.9\parskip} \setlength{\belowdisplayskip}{\parskip} \setlength{\belowdisplayshortskip}{.9\parskip} % general-purpose enum environment with correct spacing \newenvironment{enum}% {\begin{list}{}{% \setlength{\topsep}{.1\parskip}% \setlength{\partopsep}{.1\parskip}% \setlength{\itemsep}{\parskip}% \advance\itemsep by-\parsep}} {\end{list}} \def\pre{\begingroup\vskip0pt plus1ex\advance\leftskip by\leftmargin \advance\rightskip by\leftmargin} \def\post{\vskip0pt plus1ex\endgroup} \def\prew{\pre\advance\rightskip by-\leftmargin} \def\postw{\post} \section{Introduction} \label{introduction} Sledgehammer is a tool that applies automatic theorem provers (ATPs) and satisfiability-modulo-theories (SMT) solvers on the current goal.% \footnote{The distinction between ATPs and SMT solvers is convenient but mostly historical.} % The supported ATPs include agsyHOL \cite{agsyHOL}, Alt-Ergo \cite{alt-ergo}, E \cite{schulz-2002}, iProver \cite{korovin-2009}, LEO-II \cite{leo2}, Leo-III \cite{leo3}, Satallax \cite{satallax}, SPASS \cite{weidenbach-et-al-2009}, Vampire \cite{riazanov-voronkov-2002}, Waldmeister \cite{waldmeister}, and Zipperposition \cite{cruanes-2014}. The ATPs are run either locally or remotely via the System\-On\-TPTP web service \cite{sutcliffe-2000}. The supported SMT solvers are CVC3 \cite{cvc3}, CVC4 \cite{cvc4}, veriT \cite{bouton-et-al-2009}, and Z3 \cite{z3}. These are always run locally. The problem passed to the external provers (or solvers) consists of your current goal together with a heuristic selection of hundreds of facts (theorems) from the current theory context, filtered by relevance. The result of a successful proof search is some source text that typically reconstructs the proof within Isabelle. For ATPs, the reconstructed proof typically relies on the general-purpose \textit{metis} proof method, which integrates the Metis ATP in Isabelle/HOL with explicit inferences going through the kernel. Thus its results are correct by construction. For Isabelle/jEdit users, Sledgehammer provides an automatic mode that can be enabled via the ``Auto Sledgehammer'' option under ``Plugins > Plugin Options > Isabelle > General.'' In this mode, a reduced version of Sledgehammer is run on every newly entered theorem for a few seconds. \newbox\boxA \setbox\boxA=\hbox{\texttt{NOSPAM}} \newcommand\authoremail{\texttt{blan{\color{white}NOSPAM}\kern-\wd\boxA{}chette@\allowbreak in.\allowbreak tum.\allowbreak de}} To run Sledgehammer, you must make sure that the theory \textit{Sledgehammer} is imported---this is rarely a problem in practice since it is part of \textit{Main}. Examples of Sledgehammer use can be found in Isabelle's \texttt{src/HOL/Metis\_Examples} directory. Comments and bug reports concerning Sledgehammer or this manual should be directed to the author at \authoremail. \section{Installation} \label{installation} Sledgehammer is part of Isabelle, so you do not need to install it. However, it relies on third-party automatic provers (ATPs and SMT solvers). Among the ATPs, agsyHOL, Alt-Ergo, E, LEO-II, Leo-III, Satallax, SPASS, Vampire, and Zipperposition can be run locally; in addition, agsyHOL, Alt-Ergo, E, iProver, LEO-II, Leo-III, Satallax, Vampire, Waldmeister, and Zipperposition are available remotely via System\-On\-TPTP \cite{sutcliffe-2000}. The SMT solvers CVC3, CVC4, veriT, and Z3 can be run locally. There are three main ways to install automatic provers on your machine: \begin{sloppy} \begin{enum} \item[\labelitemi] If you installed an official Isabelle package, it should already include properly setup executables for CVC4, E, SPASS, Vampire, and Z3, ready to use. To use Vampire, you must confirm that you are a noncommercial user, as indicated by the message that is displayed when Sledgehammer is invoked the first time. \item[\labelitemi] Alternatively, you can download the Isabelle-aware CVC3, CVC4, E, SPASS, Vampire, and Z3 binary packages from \download. Extract the archives, then add a line to your \texttt{\$ISABELLE\_HOME\_USER\slash etc\slash components}% \footnote{The variable \texttt{\$ISABELLE\_HOME\_USER} is set by Isabelle at startup. Its value can be retrieved by executing \texttt{isabelle} \texttt{getenv} \texttt{ISABELLE\_HOME\_USER} on the command line.} file with the absolute path to CVC3, CVC4, E, SPASS, Vampire, or Z3. For example, if the \texttt{components} file does not exist yet and you extracted SPASS to \texttt{/usr/local/spass-3.8ds}, create it with the single line \prew \texttt{/usr/local/spass-3.8ds} \postw in it. \item[\labelitemi] If you prefer to build agsyHOL, Alt-Ergo, E, LEO-II, Leo-III, or Satallax manually, set the environment variable \texttt{AGSYHOL\_HOME}, \texttt{E\_HOME}, \texttt{LEO2\_HOME}, \texttt{LEO3\_HOME}, or \texttt{SATALLAX\_HOME} to the directory that contains the \texttt{agsyHOL}, \texttt{eprover} (and/or \texttt{eproof} or \texttt{eproof\_ram}), \texttt{leo}, \texttt{leo3}, or \texttt{satallax} executable; for Alt-Ergo, set the environment variable \texttt{WHY3\_HOME} to the directory that contains the \texttt{why3} executable. Sledgehammer has been tested with agsyHOL 1.0, Alt-Ergo 0.95.2, E 1.6 to 2.0, LEO-II 1.3.4, Leo-III 1.1, and Satallax 2.7. Since the ATPs' output formats are neither documented nor stable, other versions might not work well with Sledgehammer. Ideally, you should also set \texttt{E\_VERSION}, \texttt{LEO2\_VERSION}, \texttt{LEO3\_VERSION}, or \texttt{SATALLAX\_VERSION} to the prover's version number (e.g., ``2.7''); this might help Sledgehammer invoke the prover optimally. Similarly, if you want to install CVC3, CVC4, veriT, or Z3, set the environment variable \texttt{CVC3\_\allowbreak SOLVER}, \texttt{CVC4\_\allowbreak SOLVER}, \texttt{VERIT\_\allowbreak SOLVER}, or \texttt{Z3\_SOLVER} to the complete path of the executable, \emph{including the file name}. Sledgehammer has been tested with CVC3 2.2 and 2.4.1, CVC4 1.5-prerelease, veriT smtcomp2019, and Z3 4.3.2. Since Z3's output format is somewhat unstable, other versions of the solver might not work well with Sledgehammer. Ideally, also set \texttt{CVC3\_VERSION}, \texttt{CVC4\_VERSION}, \texttt{VERIT\_VERSION}, or \texttt{Z3\_VERSION} to the solver's version number (e.g., ``4.4.0''). \end{enum} \end{sloppy} To check whether the provers are successfully installed, try out the example in \S\ref{first-steps}. If the remote versions of any of these provers is used (identified by the prefix ``\textit{remote\_\/}''), or if the local versions fail to solve the easy goal presented there, something must be wrong with the installation. Remote prover invocation requires Perl with the World Wide Web Library (\texttt{libwww-perl}) installed. If you must use a proxy server to access the Internet, set the \texttt{http\_proxy} environment variable to the proxy, either in the environment in which Isabelle is launched or in your \texttt{\$ISABELLE\_HOME\_USER/etc/settings} file. Here are a few examples: \prew \texttt{http\_proxy=http://proxy.example.org} \\ \texttt{http\_proxy=http://proxy.example.org:8080} \\ \texttt{http\_proxy=http://joeblow:pAsSwRd@proxy.example.org} \postw \section{First Steps} \label{first-steps} To illustrate Sledgehammer in context, let us start a theory file and attempt to prove a simple lemma: \prew \textbf{theory}~\textit{Scratch} \\ \textbf{imports}~\textit{Main} \\ \textbf{begin} \\[2\smallskipamount] % \textbf{lemma} ``$[a] = [b] \,\Longrightarrow\, a = b$'' \\ \textbf{sledgehammer} \postw Instead of issuing the \textbf{sledgehammer} command, you can also use the Sledgehammer panel in Isabelle/jEdit. Sledgehammer produces the following output after a few seconds: \prew \slshape Proof found\ldots \\ ``\textit{e\/}'': Try this: \textbf{by} \textit{simp} (0.3 ms) \\ % ``\textit{cvc4\/}'': Try this: \textbf{by} \textit{simp} (0.4 ms) \\ % ``\textit{z3\/}'': Try this: \textbf{by} \textit{simp} (0.5 ms) \\ % ``\textit{spass\/}'': Try this: \textbf{by} \textit{simp} (0.3 ms) % \postw Sledgehammer ran CVC4, E, SPASS, and Z3 in parallel. Depending on which provers are installed and how many processor cores are available, some of the provers might be missing or present with a \textit{remote\_} prefix. For each successful prover, Sledgehammer gives a one-line \textit{metis} or \textit{smt} method call. Rough timings are shown in parentheses, indicating how fast the call is. You can click the proof to insert it into the theory text. In addition, you can ask Sledgehammer for an Isar text proof by enabling the \textit{isar\_proofs} option (\S\ref{output-format}): \prew \textbf{sledgehammer} [\textit{isar\_proofs}] \postw When Isar proof construction is successful, it can yield proofs that are more readable and also faster than the \textit{metis} or \textit{smt} one-line proofs. This feature is experimental and is only available for ATPs. \section{Hints} \label{hints} This section presents a few hints that should help you get the most out of Sledgehammer. Frequently asked questions are answered in \S\ref{frequently-asked-questions}. %\newcommand\point[1]{\medskip\par{\sl\bfseries#1}\par\nopagebreak} \newcommand\point[1]{\subsection{\emph{#1}}} \point{Presimplify the goal} For best results, first simplify your problem by calling \textit{auto} or at least \textit{safe} followed by \textit{simp\_all}. The SMT solvers provide arithmetic decision procedures, but the ATPs typically do not (or if they do, Sledgehammer does not use it yet). Apart from Waldmeister, they are not particularly good at heavy rewriting, but because they regard equations as undirected, they often prove theorems that require the reverse orientation of a \textit{simp} rule. Higher-order problems can be tackled, but the success rate is better for first-order problems. Hence, you may get better results if you first simplify the problem to remove higher-order features. \point{Familiarize yourself with the main options} Sledgehammer's options are fully documented in \S\ref{command-syntax}. Many of the options are very specialized, but serious users of the tool should at least familiarize themselves with the following options: \begin{enum} \item[\labelitemi] \textbf{\textit{provers}} (\S\ref{mode-of-operation}) specifies the automatic provers (ATPs and SMT solvers) that should be run whenever Sledgehammer is invoked (e.g., ``\textit{provers}~= \textit{cvc4 e spass vampire\/}''). For convenience, you can omit ``\textit{provers}~='' and simply write the prover names as a space-separated list (e.g., ``\textit{cvc4 e spass vampire\/}''). \item[\labelitemi] \textbf{\textit{max\_facts}} (\S\ref{relevance-filter}) specifies the maximum number of facts that should be passed to the provers. By default, the value is prover-dependent but varies between about 50 and 1000. If the provers time out, you can try lowering this value to, say, 25 or 50 and see if that helps. \item[\labelitemi] \textbf{\textit{isar\_proofs}} (\S\ref{output-format}) specifies that Isar proofs should be generated, in addition to one-line \textit{metis} or \textit{smt} proofs. The length of the Isar proofs can be controlled by setting \textit{compress} (\S\ref{output-format}). \item[\labelitemi] \textbf{\textit{timeout}} (\S\ref{timeouts}) controls the provers' time limit. It is set to 30 seconds by default. \end{enum} Options can be set globally using \textbf{sledgehammer\_params} (\S\ref{command-syntax}). The command also prints the list of all available options with their current value. Fact selection can be influenced by specifying ``$(\textit{add}{:}~\textit{my\_facts})$'' after the \textbf{sledgehammer} call to ensure that certain facts are included, or simply ``$(\textit{my\_facts})$'' to force Sledgehammer to run only with $\textit{my\_facts}$ (and any facts chained into the goal). \section{Frequently Asked Questions} \label{frequently-asked-questions} This sections answers frequently (and infrequently) asked questions about Sledgehammer. It is a good idea to skim over it now even if you do not have any questions at this stage. And if you have any further questions not listed here, send them to the author at \authoremail. \point{Which facts are passed to the automatic provers?} Sledgehammer heuristically selects a few hundred relevant lemmas from the currently loaded libraries. The component that performs this selection is called \emph{relevance filter} (\S\ref{relevance-filter}). \begin{enum} \item[\labelitemi] The traditional relevance filter, called \emph{MePo} (\underline{Me}ng--\underline{Pau}lson), assigns a score to every available fact (lemma, theorem, definition, or axiom) based upon how many constants that fact shares with the conjecture. This process iterates to include facts relevant to those just accepted. The constants are weighted to give unusual ones greater significance. MePo copes best when the conjecture contains some unusual constants; if all the constants are common, it is unable to discriminate among the hundreds of facts that are picked up. The filter is also memoryless: It has no information about how many times a particular fact has been used in a proof, and it cannot learn. \item[\labelitemi] An alternative to MePo is \emph{MaSh} (\underline{Ma}chine Learner for \underline{S}ledge\underline{h}ammer). It applies machine learning to the problem of finding relevant facts. \item[\labelitemi] The \emph{MeSh} filter combines MePo and MaSh. This is the default. \end{enum} The number of facts included in a problem varies from prover to prover, since some provers get overwhelmed more easily than others. You can show the number of facts given using the \textit{verbose} option (\S\ref{output-format}) and the actual facts using \textit{debug} (\S\ref{output-format}). Sledgehammer is good at finding short proofs combining a handful of existing lemmas. If you are looking for longer proofs, you must typically restrict the number of facts, by setting the \textit{max\_facts} option (\S\ref{relevance-filter}) to, say, 25 or 50. You can also influence which facts are actually selected in a number of ways. If you simply want to ensure that a fact is included, you can specify it using the ``$(\textit{add}{:}~\textit{my\_facts})$'' syntax. For example: % \prew \textbf{sledgehammer} (\textit{add}: \textit{hd.simps} \textit{tl.simps}) \postw % The specified facts then replace the least relevant facts that would otherwise be included; the other selected facts remain the same. If you want to direct the selection in a particular direction, you can specify the facts via \textbf{using}: % \prew \textbf{using} \textit{hd.simps} \textit{tl.simps} \\ \textbf{sledgehammer} \postw % The facts are then more likely to be selected than otherwise, and if they are selected at iteration $j$ they also influence which facts are selected at iterations $j + 1$, $j + 2$, etc. To give them even more weight, try % \prew \textbf{using} \textit{hd.simps} \textit{tl.simps} \\ \textbf{apply}~\textbf{--} \\ \textbf{sledgehammer} \postw \point{Why does Metis fail to reconstruct the proof?} There are many reasons. If Metis runs seemingly forever, that is a sign that the proof is too difficult for it. Metis's search is complete for first-order logic with equality, so if the proof was found by a superposition-based ATP such as E, SPASS, or Vampire, Metis should eventually find it, but that is little consolation. In some rare cases, \textit{metis} fails fairly quickly, and you get the error message ``One-line proof reconstruction failed.'' This indicates that Sledgehammer determined that the goal is provable, but the proof is, for technical reasons, beyond \textit{metis}'s power. You can then try again with the \textit{strict} option (\S\ref{problem-encoding}). If the goal is actually unprovable and you did not specify an unsound encoding using \textit{type\_enc} (\S\ref{problem-encoding}), this is a bug, and you are strongly encouraged to report this to the author at \authoremail. \point{How can I tell whether a suggested proof is sound?} Earlier versions of Sledgehammer often suggested unsound proofs---either proofs of nontheorems or simply proofs that rely on type-unsound inferences. This is a thing of the past, unless you explicitly specify an unsound encoding using \textit{type\_enc} (\S\ref{problem-encoding}). % Officially, the only form of ``unsoundness'' that lurks in the sound encodings is related to missing characteristic theorems of datatypes. For example, \prew \textbf{lemma}~``$\exists \mathit{xs}.\; \mathit{xs} \neq []$'' \\ \textbf{sledgehammer} () \postw suggests an argumentless \textit{metis} call that fails. However, the conjecture does actually hold, and the \textit{metis} call can be repaired by adding \textit{list.distinct}. % We hope to address this problem in a future version of Isabelle. In the meantime, you can avoid it by passing the \textit{strict} option (\S\ref{problem-encoding}). \point{What are the \textit{full\_types}, \textit{no\_types}, and \textit{mono\_tags} arguments to Metis?} The \textit{metis}~(\textit{full\_types}) proof method and its cousin \textit{metis}~(\textit{mono\_tags}) are fully-typed versions of Metis. It is somewhat slower than \textit{metis}, but the proof search is fully typed, and it also includes more powerful rules such as the axiom ``$x = \const{True} \mathrel{\lor} x = \const{False}$'' for reasoning in higher-order places (e.g., in set comprehensions). The method is automatically tried as a fallback when \textit{metis} fails, and it is sometimes generated by Sledgehammer instead of \textit{metis} if the proof obviously requires type information or if \textit{metis} failed when Sledgehammer preplayed the proof. (By default, Sledgehammer tries to run \textit{metis} with various sets of option for up to 1~second each time to ensure that the generated one-line proofs actually work and to display timing information. This can be configured using the \textit{preplay\_timeout} and \textit{dont\_preplay} options (\S\ref{timeouts}).) % At the other end of the soundness spectrum, \textit{metis} (\textit{no\_types}) uses no type information at all during the proof search, which is more efficient but often fails. Calls to \textit{metis} (\textit{no\_types}) are occasionally generated by Sledgehammer. % See the \textit{type\_enc} option (\S\ref{problem-encoding}) for details. Incidentally, if you ever see warnings such as \prew \slshape Metis: Falling back on ``\textit{metis} (\textit{full\_types})'' \postw for a successful \textit{metis} proof, you can advantageously pass the \textit{full\_types} option to \textit{metis} directly. \point{And what are the \textit{lifting} and \textit{hide\_lams} arguments to Metis?} Orthogonally to the encoding of types, it is important to choose an appropriate translation of $\lambda$-abstractions. Metis supports three translation schemes, in decreasing order of power: Curry combinators (the default), $\lambda$-lifting, and a ``hiding'' scheme that disables all reasoning under $\lambda$-abstractions. The more powerful schemes also give the automatic provers more rope to hang themselves. See the \textit{lam\_trans} option (\S\ref{problem-encoding}) for details. \point{Are the generated proofs minimal?} Automatic provers frequently use many more facts than are necessary. Sledgehammer includes a minimization tool that takes a set of facts returned by a given prover and repeatedly calls a prover or proof method with subsets of those facts to find a minimal set. Reducing the number of facts typically helps reconstruction, while also removing superfluous clutter from the proof scripts. In earlier versions of Sledgehammer, generated proofs were systematically accompanied by a suggestion to invoke the minimization tool. This step is now performed by default but can be disabled using the \textit{minimize} option (\S\ref{mode-of-operation}). \point{A strange error occurred---what should I do?} Sledgehammer tries to give informative error messages. Please report any strange error to the author at \authoremail. \point{Auto can solve it---why not Sledgehammer?} Problems can be easy for \textit{auto} and difficult for automatic provers, but the reverse is also true, so do not be discouraged if your first attempts fail. Because the system refers to all theorems known to Isabelle, it is particularly suitable when your goal has a short proof but requires lemmas that you do not know about. \point{Why are there so many options?} Sledgehammer's philosophy should work out of the box, without user guidance. Many of the options are meant to be used mostly by the Sledgehammer developers for experiments. Of course, feel free to try them out if you are so inclined. \section{Command Syntax} \label{command-syntax} \subsection{Sledgehammer} \label{sledgehammer} Sledgehammer can be invoked at any point when there is an open goal by entering the \textbf{sledgehammer} command in the theory file. Its general syntax is as follows: \prew \textbf{sledgehammer} \qty{subcommand}$^?$ \qty{options}$^?$ \qty{facts\_override}$^?$ \qty{num}$^?$ \postw In the general syntax, the \qty{subcommand} may be any of the following: \begin{enum} \item[\labelitemi] \textbf{\textit{run} (the default):} Runs Sledgehammer on subgoal number \qty{num} (1 by default), with the given options and facts. \item[\labelitemi] \textbf{\textit{supported\_provers}:} Prints the list of automatic provers supported by Sledgehammer. See \S\ref{installation} and \S\ref{mode-of-operation} for more information on how to install automatic provers. \item[\labelitemi] \textbf{\textit{refresh\_tptp}:} Refreshes the list of remote ATPs available at System\-On\-TPTP \cite{sutcliffe-2000}. \end{enum} In addition, the following subcommands provide finer control over machine learning with MaSh: \begin{enum} \item[\labelitemi] \textbf{\textit{unlearn}:} Resets MaSh, erasing any persistent state. \item[\labelitemi] \textbf{\textit{learn\_isar}:} Invokes MaSh on the current theory to process all the available facts, learning from their Isabelle/Isar proofs. This happens automatically at Sledgehammer invocations if the \textit{learn} option (\S\ref{relevance-filter}) is enabled. \item[\labelitemi] \textbf{\textit{learn\_prover}:} Invokes MaSh on the current theory to process all the available facts, learning from proofs generated by automatic provers. The prover to use and its timeout can be set using the \textit{prover} (\S\ref{mode-of-operation}) and \textit{timeout} (\S\ref{timeouts}) options. It is recommended to perform learning using a first-order ATP (such as E, SPASS, and Vampire) as opposed to a higher-order ATP or an SMT solver. \item[\labelitemi] \textbf{\textit{relearn\_isar}:} Same as \textit{unlearn} followed by \textit{learn\_isar}. \item[\labelitemi] \textbf{\textit{relearn\_prover}:} Same as \textit{unlearn} followed by \textit{learn\_prover}. \end{enum} Sledgehammer's behavior can be influenced by various \qty{options}, which can be specified in brackets after the \textbf{sledgehammer} command. The \qty{options} are a list of key--value pairs of the form ``[$k_1 = v_1, \ldots, k_n = v_n$]''. For Boolean options, ``= \textit{true\/}'' is optional. For example: \prew \textbf{sledgehammer} [\textit{isar\_proofs}, \,\textit{timeout} = 120] \postw Default values can be set using \textbf{sledgehammer\_\allowbreak params}: \prew \textbf{sledgehammer\_params} \qty{options} \postw The supported options are described in \S\ref{option-reference}. The \qty{facts\_override} argument lets you alter the set of facts that go through the relevance filter. It may be of the form ``(\qty{facts})'', where \qty{facts} is a space-separated list of Isabelle facts (theorems, local assumptions, etc.), in which case the relevance filter is bypassed and the given facts are used. It may also be of the form ``(\textit{add}:\ \qty{facts\/_{\mathrm{1}}})'', ``(\textit{del}:\ \qty{facts\/_{\mathrm{2}}})'', or ``(\textit{add}:\ \qty{facts\/_{\mathrm{1}}}\ \textit{del}:\ \qty{facts\/_{\mathrm{2}}})'', where the relevance filter is instructed to proceed as usual except that it should consider \qty{facts\/_{\mathrm{1}}} highly-relevant and \qty{facts\/_{\mathrm{2}}} fully irrelevant. If you use Isabelle/jEdit, Sledgehammer also provides an automatic mode that can be enabled via the ``Auto Sledgehammer'' option under ``Plugins > Plugin Options > Isabelle > General.'' For automatic runs, only the first prover set using \textit{provers} (\S\ref{mode-of-operation}) is considered (typically E), \textit{slice} (\S\ref{mode-of-operation}) is disabled, fewer facts are passed to the prover, \textit{fact\_filter} (\S\ref{relevance-filter}) is set to \textit{mepo}, \textit{strict} (\S\ref{problem-encoding}) is enabled, \textit{verbose} (\S\ref{output-format}) and \textit{debug} (\S\ref{output-format}) are disabled, and \textit{timeout} (\S\ref{timeouts}) is superseded by the ``Auto Time Limit'' option in jEdit. Sledgehammer's output is also more concise. \subsection{Metis} \label{metis} The \textit{metis} proof method has the syntax \prew \textbf{\textit{metis}}~(\qty{options})${}^?$~\qty{facts}${}^?$ \postw where \qty{facts} is a list of arbitrary facts and \qty{options} is a comma-separated list consisting of at most one $\lambda$ translation scheme specification with the same semantics as Sledgehammer's \textit{lam\_trans} option (\S\ref{problem-encoding}) and at most one type encoding specification with the same semantics as Sledgehammer's \textit{type\_enc} option (\S\ref{problem-encoding}). % The supported $\lambda$ translation schemes are \textit{hide\_lams}, \textit{lifting}, and \textit{combs} (the default). % All the untyped type encodings listed in \S\ref{problem-encoding} are supported. For convenience, the following aliases are provided: \begin{enum} \item[\labelitemi] \textbf{\textit{full\_types}:} Alias for \textit{poly\_guards\_query}. \item[\labelitemi] \textbf{\textit{partial\_types}:} Alias for \textit{poly\_args}. \item[\labelitemi] \textbf{\textit{no\_types}:} Alias for \textit{erased}. \end{enum} \section{Option Reference} \label{option-reference} \def\defl{\{} \def\defr{\}} \def\flushitem#1{\item[]\noindent\kern-\leftmargin \textbf{#1}} \def\optrueonly#1{\flushitem{\textit{#1} $\bigl[$= \textit{true}$\bigr]$\enskip}\nopagebreak\\[\parskip]} \def\optrue#1#2{\flushitem{\textit{#1} $\bigl[$= \qtybf{bool}$\bigr]$\enskip \defl\textit{true}\defr\hfill (neg.: \textit{#2})}\nopagebreak\\[\parskip]} \def\opfalse#1#2{\flushitem{\textit{#1} $\bigl[$= \qtybf{bool}$\bigr]$\enskip \defl\textit{false}\defr\hfill (neg.: \textit{#2})}\nopagebreak\\[\parskip]} \def\opsmart#1#2{\flushitem{\textit{#1} $\bigl[$= \qtybf{smart\_bool}$\bigr]$\enskip \defl\textit{smart}\defr\hfill (neg.: \textit{#2})}\nopagebreak\\[\parskip]} \def\opsmartx#1#2{\flushitem{\textit{#1} $\bigl[$= \qtybf{smart\_bool}$\bigr]$\enskip \defl\textit{smart}\defr\\\hbox{}\hfill (neg.: \textit{#2})}\nopagebreak\\[\parskip]} \def\opnodefault#1#2{\flushitem{\textit{#1} = \qtybf{#2}} \nopagebreak\\[\parskip]} \def\opnodefaultbrk#1#2{\flushitem{$\bigl[$\textit{#1} =$\bigr]$ \qtybf{#2}} \nopagebreak\\[\parskip]} \def\opdefault#1#2#3{\flushitem{\textit{#1} = \qtybf{#2}\enskip \defl\textit{#3}\defr} \nopagebreak\\[\parskip]} \def\oparg#1#2#3{\flushitem{\textit{#1} \qtybf{#2} = \qtybf{#3}} \nopagebreak\\[\parskip]} \def\opargbool#1#2#3{\flushitem{\textit{#1} \qtybf{#2} $\bigl[$= \qtybf{bool}$\bigr]$\hfill (neg.: \textit{#3})}\nopagebreak\\[\parskip]} \def\opargboolorsmart#1#2#3{\flushitem{\textit{#1} \qtybf{#2} $\bigl[$= \qtybf{smart\_bool}$\bigr]$\hfill (neg.: \textit{#3})}\nopagebreak\\[\parskip]} Sledgehammer's options are categorized as follows:\ mode of operation (\S\ref{mode-of-operation}), problem encoding (\S\ref{problem-encoding}), relevance filter (\S\ref{relevance-filter}), output format (\S\ref{output-format}), regression testing (\S\ref{regression-testing}), and timeouts (\S\ref{timeouts}). The descriptions below refer to the following syntactic quantities: \begin{enum} \item[\labelitemi] \qtybf{string}: A string. \item[\labelitemi] \qtybf{bool\/}: \textit{true} or \textit{false}. \item[\labelitemi] \qtybf{smart\_bool\/}: \textit{true}, \textit{false}, or \textit{smart}. \item[\labelitemi] \qtybf{int\/}: An integer. \item[\labelitemi] \qtybf{float}: A floating-point number (e.g., 2.5 or 60) expressing a number of seconds. \item[\labelitemi] \qtybf{float\_pair\/}: A pair of floating-point numbers (e.g., 0.6 0.95). \item[\labelitemi] \qtybf{smart\_int\/}: An integer or \textit{smart}. \end{enum} Default values are indicated in curly brackets (\textrm{\{\}}). Boolean options have a negative counterpart (e.g., \textit{minimize} vs.\ \textit{dont\_minimize}). When setting Boolean options or their negative counterparts, ``= \textit{true\/}'' may be omitted. \subsection{Mode of Operation} \label{mode-of-operation} \begin{enum} \opnodefaultbrk{provers}{string} Specifies the automatic provers to use as a space-separated list (e.g., ``\textit{cvc4}~\textit{e}~\textit{spass}~\textit{vampire\/}''). Provers can be run locally or remotely; see \S\ref{installation} for installation instructions. The following local provers are supported: \begin{sloppy} \begin{enum} \item[\labelitemi] \textbf{\textit{agsyhol}:} agsyHOL is an automatic higher-order prover developed by Fredrik Lindblad \cite{agsyHOL}. To use agsyHOL, set the environment variable \texttt{AGSYHOL\_HOME} to the directory that contains the \texttt{agsyHOL} executable. Sledgehammer has been tested with version 1.0. \item[\labelitemi] \textbf{\textit{alt\_ergo}:} Alt-Ergo is a polymorphic ATP developed by Bobot et al.\ \cite{alt-ergo}. It supports the TPTP polymorphic typed first-order format (TF1) via Why3 \cite{why3}. To use Alt-Ergo, set the environment variable \texttt{WHY3\_HOME} to the directory that contains the \texttt{why3} executable. Sledgehammer requires Alt-Ergo 0.95.2 and Why3 0.83. \item[\labelitemi] \textbf{\textit{cvc3}:} CVC3 is an SMT solver developed by Clark Barrett, Cesare Tinelli, and their colleagues \cite{cvc3}. To use CVC3, set the environment variable \texttt{CVC3\_SOLVER} to the complete path of the executable, including the file name, or install the prebuilt CVC3 package from \download. Sledgehammer has been tested with versions 2.2 and 2.4.1. \item[\labelitemi] \textbf{\textit{cvc4}:} CVC4 \cite{cvc4} is the successor to CVC3. To use CVC4, set the environment variable \texttt{CVC4\_SOLVER} to the complete path of the executable, including the file name, or install the prebuilt CVC4 package from \download. Sledgehammer has been tested with version 1.5-prerelease. \item[\labelitemi] \textbf{\textit{e}:} E is a first-order resolution prover developed by Stephan Schulz \cite{schulz-2002}. To use E, set the environment variable \texttt{E\_HOME} to the directory that contains the \texttt{eproof} executable and \texttt{E\_VERSION} to the version number (e.g., ``1.8''), or install the prebuilt E package from \download. Sledgehammer has been tested with versions 1.6 to 1.8. \item[\labelitemi] \textbf{\textit{iprover}:} iProver is a pure instantiation-based prover developed by Konstantin Korovin \cite{korovin-2009}. To use iProver, set the environment variable \texttt{IPROVER\_HOME} to the directory that contains the \texttt{iproveropt} executable. Sledgehammer has been tested with version 2.8. iProver depends on E to clausify problems, so make sure that E is installed as well. \item[\labelitemi] \textbf{\textit{leo2}:} LEO-II is an automatic higher-order prover developed by Christoph Benzm\"uller et al.\ \cite{leo2}, with support for the TPTP typed higher-order syntax (TH0). To use LEO-II, set the environment variable \texttt{LEO2\_HOME} to the directory that contains the \texttt{leo} executable. Sledgehammer requires version 1.3.4 or above. \item[\labelitemi] \textbf{\textit{leo3}:} Leo-III is an automatic higher-order prover developed by Alexander Steen, Max Wisniewski, Christoph Benzm\"uller et al.\ \cite{leo3}, with support for the TPTP typed higher-order syntax (TH0). To use Leo-III, set the environment variable \texttt{LEO3\_HOME} to the directory that contains the \texttt{leo3} executable. Sledgehammer requires version 1.1 or above. \item[\labelitemi] \textbf{\textit{satallax}:} Satallax is an automatic higher-order prover developed by Chad Brown et al.\ \cite{satallax}, with support for the TPTP typed higher-order syntax (TH0). To use Satallax, set the environment variable \texttt{SATALLAX\_HOME} to the directory that contains the \texttt{satallax} executable. Sledgehammer requires version 2.2 or above. \item[\labelitemi] \textbf{\textit{spass}:} SPASS is a first-order resolution prover developed by Christoph Weidenbach et al.\ \cite{weidenbach-et-al-2009}. To use SPASS, set the environment variable \texttt{SPASS\_HOME} to the directory that contains the \texttt{SPASS} executable and \texttt{SPASS\_VERSION} to the version number (e.g., ``3.8ds''), or install the prebuilt SPASS package from \download. Sledgehammer requires version 3.8ds or above. \item[\labelitemi] \textbf{\textit{vampire}:} Vampire is a first-order resolution prover developed by Andrei Voronkov and his colleagues \cite{riazanov-voronkov-2002}. To use Vampire, set the environment variable \texttt{VAMPIRE\_HOME} to the directory that contains the \texttt{vampire} executable and \texttt{VAMPIRE\_VERSION} to the version number (e.g., ``4.2.2''). Sledgehammer has been tested with versions 1.8 to 4.2.2 (in the post-2010 numbering scheme). \item[\labelitemi] \textbf{\textit{verit}:} veriT \cite{bouton-et-al-2009} is an SMT solver developed by David D\'eharbe, Pascal Fontaine, and their colleagues. It is specifically designed to produce detailed proofs for reconstruction in proof assistants. To use veriT, set the environment variable \texttt{VERIT\_SOLVER} to the complete path of the executable, including the file name. Sledgehammer has been tested with version smtcomp2019. \item[\labelitemi] \textbf{\textit{z3}:} Z3 is an SMT solver developed at Microsoft Research \cite{z3}. To use Z3, set the environment variable \texttt{Z3\_SOLVER} to the complete path of the executable, including the file name. Sledgehammer has been tested with a pre-release version of 4.4.0. \item[\labelitemi] \textbf{\textit{z3\_tptp}:} This version of Z3 pretends to be an ATP, exploiting Z3's support for the TPTP typed first-order format (TF0). It is included for experimental purposes. It requires version 4.3.1 of Z3 or above. To use it, set the environment variable \texttt{Z3\_TPTP\_HOME} to the directory that contains the \texttt{z3\_tptp} executable. \item[\labelitemi] \textbf{\textit{zipperposition}:} Zipperposition \cite{cruanes-2014} is a higher-order superposition prover developed by Simon Cruanes and colleagues. To use Zipperposition, set the environment variable \texttt{ZIPPERPOSITION\_HOME} to the directory that contains the \texttt{zipperposition} executable and \texttt{ZIPPERPOSITION\_VERSION} to the version number (e.g., ``2.0.1''). Sledgehammer has been tested with version 2.0.1. \end{enum} \end{sloppy} Moreover, the following remote provers are supported: \begin{enum} \item[\labelitemi] \textbf{\textit{remote\_agsyhol}:} The remote version of agsyHOL runs on Geoff Sutcliffe's Miami servers \cite{sutcliffe-2000}. \item[\labelitemi] \textbf{\textit{remote\_alt\_ergo}:} The remote version of Alt-Ergo runs on Geoff Sutcliffe's Miami servers \cite{sutcliffe-2000}. \item[\labelitemi] \textbf{\textit{remote\_e}:} The remote version of E runs on Geoff Sutcliffe's Miami servers \cite{sutcliffe-2000}. \item[\labelitemi] \textbf{\textit{remote\_iprover}:} The remote version of iProver runs on Geoff Sutcliffe's Miami servers \cite{sutcliffe-2000}. \item[\labelitemi] \textbf{\textit{remote\_leo2}:} The remote version of LEO-II runs on Geoff Sutcliffe's Miami servers \cite{sutcliffe-2000}. \item[\labelitemi] \textbf{\textit{remote\_leo3}:} The remote version of Leo-III runs on Geoff Sutcliffe's Miami servers \cite{sutcliffe-2000}. \item[\labelitemi] \textbf{\textit{remote\_vampire}:} The remote version of Vampire runs on Geoff Sutcliffe's Miami servers. \item[\labelitemi] \textbf{\textit{remote\_waldmeister}:} Waldmeister is a unit equality prover developed by Hillenbrand et al.\ \cite{waldmeister}. It can be used to prove universally quantified equations using unconditional equations, corresponding to the TPTP CNF UEQ division. The remote version of Waldmeister runs on Geoff Sutcliffe's Miami servers. \item[\labelitemi] \textbf{\textit{remote\_zipperposition}:} The remote version of Zipperposition runs on Geoff Sutcliffe's Miami servers. \end{enum} By default, Sledgehammer runs a subset of CVC4, E, SPASS, Vampire, veriT, and Z3 in parallel, either locally or remotely---depending on the number of processor cores available and on which provers are actually installed. It is generally desirable to run several provers in parallel. \opnodefault{prover}{string} Alias for \textit{provers}. \optrue{slice}{dont\_slice} Specifies whether the time allocated to a prover should be sliced into several segments, each of which has its own set of possibly prover-dependent options. For SPASS and Vampire, the first slice tries the fast but incomplete set-of-support (SOS) strategy, whereas the second slice runs without it. For E, up to three slices are tried, with different weighted search strategies and number of facts. For SMT solvers, several slices are tried with the same options each time but fewer and fewer facts. According to benchmarks with a timeout of 30 seconds, slicing is a valuable optimization, and you should probably leave it enabled unless you are conducting experiments. \nopagebreak {\small See also \textit{verbose} (\S\ref{output-format}).} \optrue{minimize}{dont\_minimize} Specifies whether the minimization tool should be invoked automatically after proof search. \nopagebreak {\small See also \textit{preplay\_timeout} (\S\ref{timeouts}) and \textit{dont\_preplay} (\S\ref{timeouts}).} \opfalse{spy}{dont\_spy} Specifies whether Sledgehammer should record statistics in \texttt{\$ISA\-BELLE\_\allowbreak HOME\_\allowbreak USER/\allowbreak spy\_\allowbreak sledgehammer}. These statistics can be useful to the developers of Sledgehammer. If you are willing to have your interactions recorded in the name of science, please enable this feature and send the statistics file every now and then to the author of this manual (\authoremail). To change the default value of this option globally, set the environment variable \texttt{SLEDGEHAMMER\_SPY} to \textit{yes}. \nopagebreak {\small See also \textit{debug} (\S\ref{output-format}).} \opfalse{overlord}{no\_overlord} Specifies whether Sledgehammer should put its temporary files in \texttt{\$ISA\-BELLE\_\allowbreak HOME\_\allowbreak USER}, which is useful for debugging Sledgehammer but also unsafe if several instances of the tool are run simultaneously. The files are identified by the prefixes \texttt{prob\_} and \texttt{mash\_}; you may safely remove them after Sledgehammer has run. \textbf{Warning:} This option is not thread-safe. Use at your own risks. \nopagebreak {\small See also \textit{debug} (\S\ref{output-format}).} \end{enum} \subsection{Relevance Filter} \label{relevance-filter} \begin{enum} \opdefault{fact\_filter}{string}{smart} Specifies the relevance filter to use. The following filters are available: \begin{enum} \item[\labelitemi] \textbf{\textit{mepo}:} The traditional memoryless MePo relevance filter. \item[\labelitemi] \textbf{\textit{mash}:} The MaSh machine learner. Three learning algorithms are provided: \begin{enum} \item[\labelitemi] \textbf{\textit{nb}} is an implementation of naive Bayes. \item[\labelitemi] \textbf{\textit{knn}} is an implementation of $k$-nearest neighbors. \item[\labelitemi] \textbf{\textit{nb\_knn}} (also called \textbf{\textit{yes}} and \textbf{\textit{sml}}) is a combination of naive Bayes and $k$-nearest neighbors. \end{enum} In addition, the special value \textit{none} is used to disable machine learning by default (cf.\ \textit{smart} below). The default algorithm is \textit{nb\_knn}. The algorithm can be selected by setting the ``MaSh'' option under ``Plugins > Plugin Options > Isabelle > General'' in Isabelle/jEdit. Persistent data for both algorithms is stored in the directory \texttt{\$ISABELLE\_\allowbreak HOME\_\allowbreak USER/\allowbreak mash}. \item[\labelitemi] \textbf{\textit{mesh}:} The MeSh filter, which combines the rankings from MePo and MaSh. \item[\labelitemi] \textbf{\textit{smart}:} A combination of MePo, MaSh, and MeSh. If the learning algorithm is set to be \textit{none}, \textit{smart} behaves like MePo. \end{enum} \opdefault{max\_facts}{smart\_int}{smart} Specifies the maximum number of facts that may be returned by the relevance filter. If the option is set to \textit{smart} (the default), it effectively takes a value that was empirically found to be appropriate for the prover. Typical values lie between 50 and 1000. \opdefault{fact\_thresholds}{float\_pair}{\upshape 0.45~0.85} Specifies the thresholds above which facts are considered relevant by the relevance filter. The first threshold is used for the first iteration of the relevance filter and the second threshold is used for the last iteration (if it is reached). The effective threshold is quadratically interpolated for the other iterations. Each threshold ranges from 0 to 1, where 0 means that all theorems are relevant and 1 only theorems that refer to previously seen constants. \optrue{learn}{dont\_learn} Specifies whether MaSh should be run automatically by Sledgehammer to learn the available theories (and hence provide more accurate results). Learning takes place only if MaSh is enabled. \opdefault{max\_new\_mono\_instances}{int}{smart} Specifies the maximum number of monomorphic instances to generate beyond \textit{max\_facts}. The higher this limit is, the more monomorphic instances are potentially generated. Whether monomorphization takes place depends on the type encoding used. If the option is set to \textit{smart} (the default), it takes a value that was empirically found to be appropriate for the prover. For most provers, this value is 100. \nopagebreak {\small See also \textit{type\_enc} (\S\ref{problem-encoding}).} \opdefault{max\_mono\_iters}{int}{smart} Specifies the maximum number of iterations for the monomorphization fixpoint construction. The higher this limit is, the more monomorphic instances are potentially generated. Whether monomorphization takes place depends on the type encoding used. If the option is set to \textit{smart} (the default), it takes a value that was empirically found to be appropriate for the prover. For most provers, this value is 3. \nopagebreak {\small See also \textit{type\_enc} (\S\ref{problem-encoding}).} \end{enum} \subsection{Problem Encoding} \label{problem-encoding} \newcommand\comb[1]{\const{#1}} \begin{enum} \opdefault{lam\_trans}{string}{smart} Specifies the $\lambda$ translation scheme to use in ATP problems. The supported translation schemes are listed below: \begin{enum} \item[\labelitemi] \textbf{\textit{hide\_lams}:} Hide the $\lambda$-abstractions by replacing them by unspecified fresh constants, effectively disabling all reasoning under $\lambda$-abstractions. \item[\labelitemi] \textbf{\textit{lifting}:} Introduce a new supercombinator \const{c} for each cluster of $n$~$\lambda$-abstractions, defined using an equation $\const{c}~x_1~\ldots~x_n = t$ ($\lambda$-lifting). \item[\labelitemi] \textbf{\textit{combs}:} Rewrite lambdas to the Curry combinators (\comb{I}, \comb{K}, \comb{S}, \comb{B}, \comb{C}). Combinators enable the ATPs to synthesize $\lambda$-terms but tend to yield bulkier formulas than $\lambda$-lifting: The translation is quadratic in the worst case, and the equational definitions of the combinators are very prolific in the context of resolution. \item[\labelitemi] \textbf{\textit{combs\_and\_lifting}:} Introduce a new supercombinator \const{c} for each cluster of $\lambda$-abstractions and characterize it both using a lifted equation $\const{c}~x_1~\ldots~x_n = t$ and via Curry combinators. \item[\labelitemi] \textbf{\textit{combs\_or\_lifting}:} For each cluster of $\lambda$-abstractions, heuristically choose between $\lambda$-lifting and Curry combinators. \item[\labelitemi] \textbf{\textit{keep\_lams}:} Keep the $\lambda$-abstractions in the generated problems. This is available only with provers that support the TH0 syntax. \item[\labelitemi] \textbf{\textit{smart}:} The actual translation scheme used depends on the ATP and should be the most efficient scheme for that ATP. \end{enum} For SMT solvers, the $\lambda$ translation scheme is always \textit{lifting}, irrespective of the value of this option. \opsmartx{uncurried\_aliases}{no\_uncurried\_aliases} Specifies whether fresh function symbols should be generated as aliases for applications of curried functions in ATP problems. \opdefault{type\_enc}{string}{smart} Specifies the type encoding to use in ATP problems. Some of the type encodings are unsound, meaning that they can give rise to spurious proofs (unreconstructible using \textit{metis}). The type encodings are listed below, with an indication of their soundness in parentheses. An asterisk (*) indicates that the encoding is slightly incomplete for reconstruction with \textit{metis}, unless the \textit{strict} option (described below) is enabled. \begin{enum} \item[\labelitemi] \textbf{\textit{erased} (unsound):} No type information is supplied to the ATP, not even to resolve overloading. Types are simply erased. \item[\labelitemi] \textbf{\textit{poly\_guards} (sound):} Types are encoded using a predicate \const{g}$(\tau, t)$ that guards bound variables. Constants are annotated with their types, supplied as extra arguments, to resolve overloading. \item[\labelitemi] \textbf{\textit{poly\_tags} (sound):} Each term and subterm is tagged with its type using a function $\const{t\/}(\tau, t)$. \item[\labelitemi] \textbf{\textit{poly\_args} (unsound):} Like for \textit{poly\_guards} constants are annotated with their types to resolve overloading, but otherwise no type information is encoded. This is the default encoding used by the \textit{metis} proof method. \item[\labelitemi] \textbf{% \textit{raw\_mono\_guards}, \textit{raw\_mono\_tags} (sound); \\ \textit{raw\_mono\_args} (unsound):} \\ Similar to \textit{poly\_guards}, \textit{poly\_tags}, and \textit{poly\_args}, respectively, but the problem is additionally monomorphized, meaning that type variables are instantiated with heuristically chosen ground types. Monomorphization can simplify reasoning but also leads to larger fact bases, which can slow down the ATPs. \item[\labelitemi] \textbf{% \textit{mono\_guards}, \textit{mono\_tags} (sound); \textit{mono\_args} (unsound):} \\ Similar to \textit{raw\_mono\_guards}, \textit{raw\_mono\_tags}, and \textit{raw\_mono\_args}, respectively but types are mangled in constant names instead of being supplied as ground term arguments. The binary predicate $\const{g}(\tau, t)$ becomes a unary predicate $\const{g\_}\tau(t)$, and the binary function $\const{t}(\tau, t)$ becomes a unary function $\const{t\_}\tau(t)$. \item[\labelitemi] \textbf{\textit{mono\_native} (sound):} Exploits native first-order types if the prover supports the TF0, TF1, TH0, or TH1 syntax; otherwise, falls back on \textit{mono\_guards}. The problem is monomorphized. \item[\labelitemi] \textbf{\textit{mono\_native\_higher} (sound):} Exploits native higher-order types if the prover supports the TH0 syntax; otherwise, falls back on \textit{mono\_native} or \textit{mono\_guards}. The problem is monomorphized. \item[\labelitemi] \textbf{\textit{poly\_native} (sound):} Exploits native first-order polymorphic types if the prover supports the TF1 or TH1 syntax; otherwise, falls back on \textit{mono\_native}. \item[\labelitemi] \textbf{% \textit{poly\_guards}?, \textit{poly\_tags}?, \textit{raw\_mono\_guards}?, \\ \textit{raw\_mono\_tags}?, \textit{mono\_guards}?, \textit{mono\_tags}?, \\ \textit{mono\_native}? (sound*):} \\ The type encodings \textit{poly\_guards}, \textit{poly\_tags}, \textit{raw\_mono\_guards}, \textit{raw\_mono\_tags}, \textit{mono\_guards}, \textit{mono\_tags}, and \textit{mono\_native} are fully typed and sound. For each of these, Sledgehammer also provides a lighter variant identified by a question mark (`\hbox{?}')\ that detects and erases monotonic types, notably infinite types. (For \textit{mono\_native}, the types are not actually erased but rather replaced by a shared uniform type of individuals.) As argument to the \textit{metis} proof method, the question mark is replaced by a \hbox{``\textit{\_query\/}''} suffix. \item[\labelitemi] \textbf{% \textit{poly\_guards}??, \textit{poly\_tags}??, \textit{raw\_mono\_guards}??, \\ \textit{raw\_mono\_tags}??, \textit{mono\_guards}??, \textit{mono\_tags}?? \\ (sound*):} \\ Even lighter versions of the `\hbox{?}' encodings. As argument to the \textit{metis} proof method, the `\hbox{??}' suffix is replaced by \hbox{``\textit{\_query\_query\/}''}. \item[\labelitemi] \textbf{% \textit{poly\_guards}@, \textit{poly\_tags}@, \textit{raw\_mono\_guards}@, \\ \textit{raw\_mono\_tags}@ (sound*):} \\ Alternative versions of the `\hbox{??}' encodings. As argument to the \textit{metis} proof method, the `\hbox{@}' suffix is replaced by \hbox{``\textit{\_at\/}''}. \item[\labelitemi] \textbf{\textit{poly\_args}?, \textit{raw\_mono\_args}? (unsound):} \\ Lighter versions of \textit{poly\_args} and \textit{raw\_mono\_args}. \item[\labelitemi] \textbf{\textit{smart}:} The actual encoding used depends on the ATP and should be the most efficient sound encoding for that ATP. \end{enum} For SMT solvers, the type encoding is always \textit{mono\_native}, irrespective of the value of this option. \nopagebreak {\small See also \textit{max\_new\_mono\_instances} (\S\ref{relevance-filter}) and \textit{max\_mono\_iters} (\S\ref{relevance-filter}).} \opfalse{strict}{non\_strict} Specifies whether Sledgehammer should run in its strict mode. In that mode, sound type encodings marked with an asterisk (*) above are made complete for reconstruction with \textit{metis}, at the cost of some clutter in the generated problems. This option has no effect if \textit{type\_enc} is deliberately set to an unsound encoding. \end{enum} \subsection{Output Format} \label{output-format} \begin{enum} \opfalse{verbose}{quiet} Specifies whether the \textbf{sledgehammer} command should explain what it does. \opfalse{debug}{no\_debug} Specifies whether Sledgehammer should display additional debugging information beyond what \textit{verbose} already displays. Enabling \textit{debug} also enables \textit{verbose} behind the scenes. \nopagebreak {\small See also \textit{spy} (\S\ref{mode-of-operation}) and \textit{overlord} (\S\ref{mode-of-operation}).} \opsmart{isar\_proofs}{no\_isar\_proofs} Specifies whether Isar proofs should be output in addition to one-line proofs. The construction of Isar proof is still experimental and may sometimes fail; however, when they succeed they are usually faster and more intelligible than one-line proofs. If the option is set to \textit{smart} (the default), Isar proofs are only generated when no working one-line proof is available. \opdefault{compress}{int}{smart} Specifies the granularity of the generated Isar proofs if \textit{isar\_proofs} is explicitly enabled. A value of $n$ indicates that each Isar proof step should correspond to a group of up to $n$ consecutive proof steps in the ATP proof. If the option is set to \textit{smart} (the default), the compression factor is 10 if the \textit{isar\_proofs} option is explicitly enabled; otherwise, it is $\infty$. \optrueonly{dont\_compress} Alias for ``\textit{compress} = 1''. \optrue{try0}{dont\_try0} Specifies whether standard proof methods such as \textit{auto} and \textit{blast} should be tried as alternatives to \textit{metis} in Isar proofs. The collection of methods is roughly the same as for the \textbf{try0} command. \optrue{smt\_proofs}{no\_smt\_proofs} Specifies whether the \textit{smt} proof method should be tried in addition to Isabelle's built-in proof methods. \end{enum} \subsection{Regression Testing} \label{regression-testing} \begin{enum} \opnodefault{expect}{string} Specifies the expected outcome, which must be one of the following: \begin{enum} \item[\labelitemi] \textbf{\textit{some}:} Sledgehammer found a proof. \item[\labelitemi] \textbf{\textit{none}:} Sledgehammer found no proof. \item[\labelitemi] \textbf{\textit{timeout}:} Sledgehammer timed out. \item[\labelitemi] \textbf{\textit{unknown}:} Sledgehammer encountered some problem. \end{enum} Sledgehammer emits an error if the actual outcome differs from the expected outcome. This option is useful for regression testing. \nopagebreak {\small See also \textit{timeout} (\S\ref{timeouts}).} \end{enum} \subsection{Timeouts} \label{timeouts} \begin{enum} \opdefault{timeout}{float}{\upshape 30} Specifies the maximum number of seconds that the automatic provers should spend searching for a proof. This excludes problem preparation and is a soft limit. \opdefault{preplay\_timeout}{float}{\upshape 1} Specifies the maximum number of seconds that \textit{metis} or other proof methods should spend trying to ``preplay'' the found proof. If this option is set to 0, no preplaying takes place, and no timing information is displayed next to the suggested proof method calls. \nopagebreak {\small See also \textit{minimize} (\S\ref{mode-of-operation}).} \optrueonly{dont\_preplay} Alias for ``\textit{preplay\_timeout} = 0''. \end{enum} \section{Mirabelle Testing Tool} \label{mirabelle} -% using Sledgehammer or other advisory tools -% proof tools or counterexample generator -The \texttt{isabelle mirabelle} tool executes Sledgehammer, or other advisory -tools (e.g. proof tools, counterexample generators) on most subgoals in a theory. -It is typically used to quantify the success rate of a proof tool on a -representative benchmark. Its command-line usage is: +The \texttt{isabelle mirabelle} tool executes Sledgehammer or other advisory +tools (e.g., Nitpick) or tactics (e.g., \textit{auto}) on all subgoals emering +in a theory. It is typically used to measure the success rate of a proof tool +on some benchmark. Its command-line usage is as follows: {\small \begin{verbatim} isabelle mirabelle [OPTIONS] ACTIONS FILES Options are: -L LOGIC parent logic to use (default HOL) -O DIR output directory for test data (default None) -S FILE user-provided setup file (no actions required) -T THEORY parent theory to use (default Main) -d DIR include session directory -q be quiet (suppress output of Isabelle process) -t TIMEOUT timeout for each action in seconds (default 30) Apply the given actions at all proof steps in the given theory files. \end{verbatim} } Option \texttt{-L LOGIC} specifies the parent session to use. This is often a -logic (e.g. Pure, HOL) but may be any session (e.g. from the AFP). Using -multiple sessions is not supported at the moment. If a theory A needs to import -from multiple sessions, this limitation can be overcome by +logic (e.g., \texttt{Pure}, \texttt{HOL}) but may be any session (e.g., from +the AFP). Using multiple sessions is not supported. If a theory A needs to +import theories from multiple sessions, this limitation can be overcome as +follows: \begin{enumerate} - \item defining a custom session S with a single theory B; - \item moving all imports from A to B; - \item building the heap image of S; - \item importing S.B from theory A; - \item executing Mirabelle with C as parent logic, i.e. with \texttt{-L S}. + \item Define a custom session \texttt{S} with a single theory \texttt{B}. + \item Move all imports from \texttt{A} to \texttt{B}. + \item Build the heap image of \texttt{S}. + \item Import \texttt{S.B} from theory \texttt{A}. + \item Execute Mirabelle with \texttt{C} as parent logic (i.e., with + \texttt{-L S}). \end{enumerate} -Option \texttt{-O DIR} specifies the output directory, which is created if not -already existing, where the log will be written. In this directory, one log -file per theory records the position of each tested subgoal and the result of -executing the proof tool. +Option \texttt{-O DIR} specifies the output directory, which is created if +needed. In this directory, one log file per theory records the position of each +tested subgoal and the result of executing the action. -Option \texttt{-t TIMEOUT} specifies a generic timeout that different actions -may interpret in different ways. +Option \texttt{-t TIMEOUT} specifies a generic timeout that the actions may +interpret differently. -More specific documentation about parameters \texttt{ACTIONS}, \texttt{FILES}, -and their corresponding options may be found in the isabelle tool usage by -entering \texttt{isabelle mirabelle -?} on the command line. +More specific documentation about the \texttt{ACTIONS} and \texttt{FILES} +parameters and their corresponding options can be found in the Isabelle tool +usage by entering \texttt{isabelle mirabelle -?} on the command line. \subsection{Example of Benchmarking Sledgehammer} \begin{verbatim} -isabelle mirabelle -O output \ +isabelle mirabelle -O output/ \ sledgehammer[prover=e,prover_timeout=10] Huffman.thy \end{verbatim} -This command benchmarks sledgehammer when using \textbf{\textit{e}} as prover -with a timeout of 10 seconds. The results are written to the file +This command specifies Sledgehammer as the action, using E as the prover with a +timeout of 10 seconds. The results are written to the file \texttt{output/Huffman.log}. -\subsection{Example of Benchmarking Other Tools} +\subsection{Example of Benchmarking Another Tool} \begin{verbatim} -isabelle mirabelle -O output -t 10 \ - try0 Huffman.thy +isabelle mirabelle -O output/ -t 10 try0 Huffman.thy \end{verbatim} -This command benchmarks the \texttt{try0} tactic with a timeout of 10 seconds. -The results are written to the file \texttt{output/Huffman.log}. +This command specifies the \textbf{try0} command as the action, with a timeout +of 10 seconds. The results are written to the file \texttt{output/Huffman.log}. \subsection{Example of Generating TPTP Files} \begin{verbatim} -isabelle mirabelle -O output \ - sledgehammer[prover_timeout=1,keep=tptp-files] Huffman.thy +isabelle mirabelle -O output/ \ + sledgehammer[prover=e,prover_timeout=1,keep=/tptp/files/] \ + Huffman.thy \end{verbatim} -This command generates TPTP files with sledgehammer. Since the file is -generated at the very beginning of every sledgehammer invocation, a timeout of -1 second making the prover fail faster speeds handling the theory up. The -results are written in the \texttt{tptp-files} directory, which has to exist -prior to the command invocation. A distinct TPTP file is generated for each -subgoal with a file name ending with \texttt{.smt\_in}. +This command generates TPTP files using Sledgehammer. Since the file is +generated at the very beginning of every Sledgehammer invocation, a timeout of +one second making the prover fail faster speeds up processing the theory. The +results are written in the specified directory (\texttt{/tptp/files/}), +which must exist beforehand. A TPTP file is generated for each subgoal. \let\em=\sl \bibliography{manual}{} \bibliographystyle{abbrv} \end{document}