(*<*) theory "01_Introduction" imports "00_Frontmatter" begin (*>*) chapter*[intro::introduction]\ Introduction \ text*[introtext::introduction]\ The linking of the \<^emph>\formal\ to the \<^emph>\informal\ is perhaps the most pervasive challenge in the digitization of knowledge and its propagation. This challenge incites numerous research efforts summarized under the labels ``semantic web'', ``data mining'', or any form of advanced ``semantic'' text processing. A key role in structuring this linking play \<^emph>\document ontologies\ (also called \<^emph>\vocabulary\ in the semantic web community~@{cite "w3c:ontologies:2015"}), \ie, a machine-readable form of the structure of documents as well as the document discourse. Such ontologies can be used for the scientific discourse within scholarly articles, mathematical libraries, and in the engineering discourse of standardized software certification documents~@{cite "boulanger:cenelec-50128:2015" and "cc:cc-part3:2006"}. Further applications are the domain-specific discourse in juridical texts or medical reports. In general, an ontology is a formal explicit description of \<^emph>\concepts\ in a domain of discourse (called \<^emph>\classes\), properties of each concept describing \<^emph>\attributes\ of the concept, as well as \<^emph>\links\ between them. A particular link between concepts is the \<^emph>\is-a\ relation declaring the instances of a subclass to be instances of the super-class. The main objective of this paper is to present \isadof, a novel framework to \<^emph>\model\ typed ontologies and to \<^emph>\enforce\ them during document evolution. Based on Isabelle infrastructures, ontologies may refer to types, terms, proven theorems, code, or established assertions. Based on a novel adaption of the Isabelle IDE, a document is checked to be \<^emph>\conform\ to a particular ontology---\isadof is designed to give fast user-feedback \<^emph>\during the capture of content\. This is particularly valuable in case of document evolution, where the \<^emph>\coherence\ between the formal and the informal parts of the content can be mechanically checked. To avoid any misunderstanding: \isadof is \<^emph>\not a theory in HOL\ on ontologies and operations to track and trace links in texts, it is an \<^emph>\environment to write structured text\ which \<^emph>\may contain\ Isabelle/HOL definitions and proofs like mathematical articles, tech-reports and scientific papers---as the present one, which is written in \isadof itself. \isadof is a plugin into the Isabelle/Isar framework in the style of~@{cite "wenzel.ea:building:2007"}.\ text\This manual adresses at three different types of users: \<^enum> users that just want to edit a core document, be it for a paper or a technical report, using a given ontology, \<^enum> users that want to develop ontologies and/or modify the generated PDF-presentations, \<^enum> users that want to add text-elements or new features to \isadof. This manual gives priority to the former two groups; users with an interest in \isadof implementation might find complementary information in @{cite "brucker.wolff19:isadof-design-impl:2019"}. \ (* declaring the forward references used in the subsequent section *) (*<*) declare_reference*[bgrnd::text_section] declare_reference*[isadof::text_section] declare_reference*[casestudies::text_section] declare_reference*[latex::text_section] declare_reference*[conclusion::text_section] (*>*) text*[plan::introduction]\ The plan of the paper is follows: we start by introducing the underlying Isabelle system (@{docitem_ref (unchecked) \bgrnd\}) followed guided tour or tutorial adressing the needs of the first intended user group. It follows the chapter @{docitem_ref (unchecked) \isadof\} for the first user group needing a more systematic introduction as well as the second user group with essentials of \isadof and its ontology language (@{docitem_ref (unchecked) \isadof\}). It follows @{docitem_ref (unchecked) \latex\}, where we necessary bits on the LaTeX generation and ways to adapt it to particular purposes. Finally, we draw conclusions and discuss related work in @{docitem_ref (unchecked) \conclusion\}. \ (*<*) end (*>*)