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author | wenzelm |

Mon, 17 Jun 2013 20:15:34 +0200 | |

changeset 52411 | f192c4ea5b17 |

parent 52410 | fb1fb867c146 |

child 52412 | 4cfa094da3cb |

more on reconstructing and checking proof terms;

--- a/src/Doc/IsarImplementation/Logic.thy Mon Jun 17 19:30:41 2013 +0200 +++ b/src/Doc/IsarImplementation/Logic.thy Mon Jun 17 20:15:34 2013 +0200 @@ -1273,11 +1273,35 @@ without the full overhead of explicit proof terms. *} + +subsection {* Reconstructing and checking proof terms *} + +text {* Fully explicit proof terms can be large, but most of this + information is redundant and can be reconstructed from the context. + Therefore, the Isabelle/Pure inference kernel records only + \emph{implicit} proof terms, by omitting all typing information in + terms, all term and type labels of proof abstractions, and some + argument terms of applications @{text "p \<cdot> t"} (if possible). + + There are separate operations to reconstruct the full proof term + later on, using \emph{higher-order pattern unification} + \cite{nipkow-patterns,Berghofer-Nipkow:2000:TPHOL}. + + The \emph{proof checker} expects a fully reconstructed proof term, + and can turn it into a theorem by replaying its primitive inferences + within the kernel. *} + text %mlref {* \begin{mldecls} @{index_ML_type proof} \\ @{index_ML_type proof_body} \\ @{index_ML proofs: "int Unsynchronized.ref"} \\ + @{index_ML Reconstruct.reconstruct_proof: + "theory -> term -> proof -> proof"} \\ + @{index_ML Reconstruct.expand_proof: "theory -> + (string * term option) list -> proof -> proof"} \\ + @{index_ML Proof_Checker.thm_of_proof: + "theory -> proof -> thm"} \\ \end{mldecls} \begin{description} @@ -1311,6 +1335,25 @@ Officially named theorems that contribute to a result are recorded in any case. + \item @{ML Reconstruct.reconstruct_proof}~@{text "thy prop prf"} + turns the implicit proof term @{text "prf"} into a full proof of the + given proposition. + + Reconstruction may fail if @{text "prf"} is not a proof of @{text + "prop"}, or if it does not contain sufficient information for + reconstruction. Failure may only happen for proofs that are + constructed manually, but not for those produced automatically by + the inference kernel. + + \item @{ML Reconstruct.expand_proof}~@{text "thy [thm\<^sub>1, \<dots>, thm\<^sub>n] + prf"} expands and reconstructs the proofs of all specified theorems, + with the given (full) proof. Theorems that are not unique specified + via their name may be disambiguated by giving their proposition. + + \item @{ML Proof_Checker.thm_of_proof}~@{text "thy prf"} turns the + given (full) proof into a theorem, by replaying it using only + primitive rules of the inference kernel. + \end{description} *}

--- a/src/Doc/Ref/document/root.tex Mon Jun 17 19:30:41 2013 +0200 +++ b/src/Doc/Ref/document/root.tex Mon Jun 17 20:15:34 2013 +0200 @@ -25,7 +25,8 @@ \emph{Note}: this document is part of the earlier Isabelle documentation and is mostly outdated. Fully obsolete parts of the original text have already been removed. The remaining material -covers some aspects that did not make it into the newer manuals yet. +covers some aspects that did not make it into the newer manuals yet +\cite{isabelle-isar-ref,isabelle-implementation}. \subsubsection*{Acknowledgements} Tobias Nipkow, of T. U. Munich, wrote most of

--- a/src/Doc/Ref/document/thm.tex Mon Jun 17 19:30:41 2013 +0200 +++ b/src/Doc/Ref/document/thm.tex Mon Jun 17 20:15:34 2013 +0200 @@ -3,49 +3,6 @@ \section{Proof terms}\label{sec:proofObjects} -\subsection{Reconstructing and checking proof terms}\label{sec:reconstruct_proofs} -\index{proof terms!reconstructing} -\index{proof terms!checking} - -When looking at the above datatype of proofs more closely, one notices that -some arguments of constructors are {\it optional}. The reason for this is that -keeping a full proof term for each theorem would result in enormous memory -requirements. Fortunately, typical proof terms usually contain quite a lot of -redundant information that can be reconstructed from the context. Therefore, -Isabelle's inference kernel creates only {\em partial} (or {\em implicit}) -\index{proof terms!partial} proof terms, in which -all typing information in terms, all term and type labels of abstractions -{\tt AbsP} and {\tt Abst}, and (if possible) some argument terms of -\verb!%! are omitted. The following functions are available for -reconstructing and checking proof terms: -\begin{ttbox} -Reconstruct.reconstruct_proof : - Sign.sg -> term -> Proofterm.proof -> Proofterm.proof -Reconstruct.expand_proof : - Sign.sg -> string list -> Proofterm.proof -> Proofterm.proof -ProofChecker.thm_of_proof : theory -> Proofterm.proof -> thm -\end{ttbox} - -\begin{ttdescription} -\item[Reconstruct.reconstruct_proof $sg$ $t$ $prf$] -turns the partial proof $prf$ into a full proof of the -proposition denoted by $t$, with respect to signature $sg$. -Reconstruction will fail with an error message if $prf$ -is not a proof of $t$, is ill-formed, or does not contain -sufficient information for reconstruction by -{\em higher order pattern unification} -\cite{nipkow-patterns, Berghofer-Nipkow:2000:TPHOL}. -The latter may only happen for proofs -built up ``by hand'' but not for those produced automatically -by Isabelle's inference kernel. -\item[Reconstruct.expand_proof $sg$ - \ttlbrack$name@1$, $\ldots$, $name@n${\ttrbrack} $prf$] -expands and reconstructs the proofs of all theorems with names -$name@1$, $\ldots$, $name@n$ in the (full) proof $prf$. -\item[ProofChecker.thm_of_proof $thy$ $prf$] turns the (full) proof -$prf$ into a theorem with respect to theory $thy$ by replaying -it using only primitive rules from Isabelle's inference kernel. -\end{ttdescription} \subsection{Parsing and printing proof terms} \index{proof terms!parsing}