The signed book

Original fiction extract.

The librarian scrutinised the signature on the title page. The bookseller had described it as the author’s, but I had written something very similar in a birthday card to my sister. She fetched a magnifying glass and a reference book instead of announcing an answer. One letter curved differently from the printed example. That did not settle it, she said, because signatures changed. I had come hoping for a simple yes or no. She gave me a list of details to check with the seller.

Identify a word or phrase from the extract which suggests the same idea as the words in bold:

The librarian examined very carefully the signature on the title page.