# Alloy Authors - Practical Alloy - Signature facts (Highlights) ![rw-book-cover|256](https://readwise-assets.s3.amazonaws.com/static/images/article4.6bc1851654a0.png) ## Highlights - The variable implicitly quantified is always called `this`, and you can call it within signature facts if needed. ([View Highlight](https://read.readwise.io/read/01jtx4vydm8absgtadaqse2y8n)) ^887867997