# Software Abstractions

**URL:** https://alloytools.discourse.group/c/daniel-jacksons-seminal-book-about-alloy/11.md

[Latest](https://alloytools.discourse.group/latest.md) · [Categories](https://alloytools.discourse.group/categories.md)

---

## [About the Software Abstractions category](https://alloytools.discourse.group/t/about-the-software-abstractions-category/83)

<div class="topic-metadata">

**Author:** [@peter.kriens](https://alloytools.discourse.group/u/peter.kriens)\
**Replies:** 0

</div>

Daniel Jackson wrote the book about Alloy: Software Abstractions. This category discusses questions and ideas related to this book.

---

## [Multiplicity Keyword in Subset Constraint](https://alloytools.discourse.group/t/multiplicity-keyword-in-subset-constraint/539)

<div class="topic-metadata">

**Author:** [@jackc](https://alloytools.discourse.group/u/jackc)\
**Replies:** 1\
**Last updated:** [February 21, 2026, 10:06am UTC](https://alloytools.discourse.group/t/multiplicity-keyword-in-subset-constraint/539 "2026-02-21T10:06:37Z")

</div>

Hi, I am encountering a problem with using Multiplicity keywords within a subset constraint. In the Software Abstractions Revised edition, on bottom page 275 it says In either a declaration decl ::= \[disj\] name,+ : \[…

---

## [Alloy library for software engineers?](https://alloytools.discourse.group/t/alloy-library-for-software-engineers/257)

<div class="topic-metadata">

**Author:** [@chadbrewbaker](https://alloytools.discourse.group/u/chadbrewbaker)\
**Replies:** 2\
**Last updated:** [October 11, 2022, 3:48pm UTC](https://alloytools.discourse.group/t/alloy-library-for-software-engineers/257 "2022-10-11T15:48:10Z")

</div>

Is there a repository with a more comprehensive set of Alloy models for web/server protocols? Eunsuk Kang has Alloy files for web browser same origin policies and another for OAuth2 on his GitHub. Jay Parlar mentioned …

---

## [Trying to model a Filesystem](https://alloytools.discourse.group/t/trying-to-model-a-filesystem/98)

<div class="topic-metadata">

**Author:** [@Zenzi](https://alloytools.discourse.group/u/Zenzi)\
**Replies:** 8\
**Last updated:** [September 20, 2020, 7:10pm UTC](https://alloytools.discourse.group/t/trying-to-model-a-filesystem/98 "2020-09-20T19:10:32Z")

</div>

Hi, after reading chapter 2 and 3, I tried to practice Alloy a bit further. My goal is to model a simple filesystem and I started with creating a basic “structure” with files, folders and so on (based on this). /\* ---…

---

## [Alloy book - Question on figure 2.6/page 14](https://alloytools.discourse.group/t/alloy-book-question-on-figure-2-6-page-14/82)

<div class="topic-metadata">

**Author:** [@Zenzi](https://alloytools.discourse.group/u/Zenzi)\
**Replies:** 6\
**Last updated:** [September 8, 2020, 9:04pm UTC](https://alloytools.discourse.group/t/alloy-book-question-on-figure-2-6-page-14/82 "2020-09-08T21:04:27Z")

</div>

Hi, I just started reading the Software Abstractions book. I am on page 14, figure 2.6: Can anyone explain how to generate the chart at the bottom with the Alloy Analyzer? When I am running the model, I am only seeing…