DIG interface does not support provides complex role inclusion

[Dmitry Tsarkov]

Original [issue 8](https://code.google.com/p/factplusplus/issues/detail?id=8) created by dtsarkov on 2007-12-10T12:23:26.000Z:

<b>What steps will reproduce the problem?</b> &lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; ?&gt; - &lt;tells uri=&quot;http://dl.kr.org/dig/FaCTpp-007_13-22-26_10-12-2007&quot;&gt; &lt;defrole name=&quot;a&quot; /&gt; &lt;defrole name=&quot;b&quot; /&gt; &lt;defrole name=&quot;c&quot; /&gt; - &lt;impliesr&gt; &lt;ratom name=&quot;a&quot; /&gt; - &lt;chain&gt; &lt;ratom name=&quot;b&quot; /&gt; &lt;ratom name=&quot;c&quot; /&gt; &lt;/chain&gt; &lt;/impliesr&gt; &lt;/tells&gt;

<b>What is the expected output? What do you see instead?</b> definition of complex role inclusion

[Dmitry Tsarkov]

Comment [#1](https://code.google.com/p/factplusplus/issues/detail?id=8#c1) originally posted by dtsarkov on 2007-12-12T15:02:21.000Z:

There is no possibility to define role inclusion axioms in DIG 1.1. The <chain> construction has a syntax <chain> F1 F2 ... Fn A</chain>, where F1 ... Fn are features (functional roles) and A is an attribute (data role). The feature chain has a semantics of an attribute, and can only be used in an attribute-related concept expressions.