author wenzelm
Thu, 27 Aug 1998 11:51:32 +0200
changeset 5384 c974451df466
parent 5243 a0688fa916af
child 6257 ee0b48ab5aea
permissions -rw-r--r--
href eps versions;


<!-- $Id$ -->

<title>The Isabelle Logo</title>


<h1>The Isabelle Logo</h1>


The logo is available for the generic Isabelle system (<a
href="#plain">plain</a>, <a href="#transparent">transparent</a>) and
major object logics (<a href="#ZF">ZF</a>, <a href="#HOL">HOL</a>, <a
href="#HOLCF">HOLCF</a>).  There are also <a
href="isabelle-small.xpm">small</a> and <a
href="isabelle-tiny.xpm">tiny</a> Isabelle icons available.
Furthermore, there are EPS versions of the <a
href="isabelle.eps">plain</a> and the <a
href="isabelle_hol.eps">HOL</a> Isabelle logo.


<img src="isabelle.gif" align=right alt="[Isabelle logo]"> First of
all, the logo tells about the name of the generic system, Isabelle, or
of its concrete instantiations, e.g. Isabelle/HOL.  It also expresses
some essentials of the overall Isabelle design philosophy: Composition
of several small well understood building blocks, grouped together or
arranged in layers. <p>

The markings on the cubes illustrate this general principle by example
of the core meta-logic (which is minimal higher-order logic on top of
naively polymorphic simply typed lambda calculus). Thus red cubes
symbolize the type system with function spaces (->) and type variables
(alpha); violet ones represent the lambda term language with beta
conversion etc.; yellow cubes constitute the actual logical parts,
namely meta-implication or entailment (|-) and meta-level universal


The logo is contributed by <a
Wenzel</a>, Munich.  It has been designed on Apple Macintosh. <p>


<a name="plain"><img src="isabelle.gif" alt="[Isabelle logo]"></a> <p>

<a name="transparent"><img src="isabelle_transparent.gif"
alt="[Isabelle logo (transparent)]"></a> Note: This may look bad on
black and white displays.  <p>

<a name="ZF"><img src="isabelle_zf.gif" alt="[Isabelle logo
(ZF)]"></a> <p>

<a name="HOL"><img src="isabelle_hol.gif" alt="[Isabelle logo
(HOL)]"></a> <p>

<a name="HOLCF"><img src="isabelle_holcf.gif" alt="[Isabelle logo
(HOLCF)]"></a> <p>