doc-src/IsarImplementation/Thy/logic.thy
author wenzelm
Mon Jan 02 20:16:52 2006 +0100 (2006-01-02)
changeset 18537 2681f9e34390
child 20437 0eb5e30fd620
permissions -rw-r--r--
"The Isabelle/Isar Implementation" manual;
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(* $Id$ *)
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theory logic imports base begin
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chapter {* Pure logic *}
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section {* Syntax *}
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subsection {* Simply-typed lambda calculus *}
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text {*
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FIXME
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\glossary{Type}{FIXME}
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\glossary{Term}{FIXME}
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*}
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subsection {* The order-sorted algebra of types *}
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text {*
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FIXME
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\glossary{Type constructor}{FIXME}
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\glossary{Type class}{FIXME}
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\glossary{Type arity}{FIXME}
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\glossary{Sort}{FIXME}
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*}
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subsection {* Type-inference and schematic polymorphism *}
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text {*
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FIXME
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\glossary{Schematic polymorphism}{FIXME}
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\glossary{Type variable}{FIXME}
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*}
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section {* Theory *}
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text {*
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FIXME
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\glossary{Constant}{Essentially a \seeglossary{fixed variable} of the
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theory context, but slightly more flexible since it may be used at
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different type-instances, due to \seeglossary{schematic
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polymorphism.}}
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*}
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section {* Deduction *}
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text {*
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  FIXME
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\glossary{Proposition}{A \seeglossary{term} of \seeglossary{type}
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@{text "prop"}.  Internally, there is nothing special about
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propositions apart from their type, but the concrete syntax enforces a
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clear distinction.  Propositions are structured via implication @{text
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"A \<Longrightarrow> B"} or universal quantification @{text "\<And>x. B x"} --- anything
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else is considered atomic.  The canonical form for propositions is
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that of a \seeglossary{Hereditary Harrop Formula}.}
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\glossary{Theorem}{A proven proposition within a certain theory and
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proof context, formally @{text "\<Gamma> \<turnstile>\<^sub>\<Theta> \<phi>"}; both contexts are
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rarely spelled out explicitly.  Theorems are usually normalized
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according to the \seeglossary{HHF} format.}
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\glossary{Fact}{Sometimes used interchangably for
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\seeglossary{theorem}.  Strictly speaking, a list of theorems,
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essentially an extra-logical conjunction.  Facts emerge either as
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local assumptions, or as results of local goal statements --- both may
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be simultaneous, hence the list representation.}
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\glossary{Schematic variable}{FIXME}
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\glossary{Fixed variable}{A variable that is bound within a certain
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proof context; an arbitrary-but-fixed entity within a portion of proof
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text.}
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\glossary{Free variable}{Synonymous for \seeglossary{fixed variable}.}
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\glossary{Bound variable}{FIXME}
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\glossary{Variable}{See \seeglossary{schematic variable},
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\seeglossary{fixed variable}, \seeglossary{bound variable}, or
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\seeglossary{type variable}.  The distinguishing feature of different
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variables is their binding scope.}
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*}
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subsection {* Primitive inferences *}
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text FIXME
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subsection {* Higher-order resolution *}
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text {*
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FIXME
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\glossary{Hereditary Harrop Formula}{The set of propositions in HHF
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format is defined inductively as @{text "H = (\<And>x\<^sup>*. H\<^sup>* \<Longrightarrow>
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A)"}, for variables @{text "x"} and atomic propositions @{text "A"}.
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Any proposition may be put into HHF form by normalizing with the rule
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@{text "(A \<Longrightarrow> (\<And>x. B x)) \<equiv> (\<And>x. A \<Longrightarrow> B x)"}.  In Isabelle, the outermost
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quantifier prefix is represented via \seeglossary{schematic
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variables}, such that the top-level structure is merely that of a
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\seeglossary{Horn Clause}}.
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\glossary{HHF}{See \seeglossary{Hereditary Harrop Formula}.}
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*}
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subsection {* Equational reasoning *}
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text FIXME
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section {* Proof terms *}
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text FIXME
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end