I am a beginner in German and this is my first post. 
I encounter the following sentence in a German article:

> In vielen Fällen folgt diese Eigenschaft aus Satz 1, die Gegenstand dieses Kapitels ist.

I can not understand the use of "**die**" in front of "**Gegenstand**"(subject, topic, theme, etc.). 
According to the [online dictionary](https://en.wiktionary.org/wiki/Gegenstand),  "Gegenstand" is masculine, and the only two cases of a leading "die" are: nominative plural and accusative plural, where the word should be "**Gegenstände**".

Is "die Gegenstand" grammatically correct ?