proof
noun
evidence sufficient to establish a thing as true, or to produce belief in its truth.
Used to express a completed action that took place before another specific past action occurred.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
I had proofed several books, but never thought to look closely at formatting decisions.
From The Project Gutenberg FAQ 2002 by Jim Tinsley