TITLE: What is unitary space
QUESTION [5 upvotes]: In https://www.encyclopediaofmath.org/index.php/Unitary_space, unitary space seems to be Hilbert space. But in http://www.answers.com/topic/unitary-space, "finite dimensional" is required. My question is, which definition of unitary space is commonly used?

REPLY [14 votes]: Answers.com is wrong. Unitary space is an archaic name for complex inner product space.