Hilbert space, a Rare card

The card carries these facts from its Wikipedia article.

• It extends the methods of Euclidean geometry and calculus from the two-dimensional Euclidean plane and three-dimensional space to spaces of any finite or infinite dimension.
• A Hilbert space is an abstract vector space, and it has the additional structure of an inner product that allows length and angle to be measured.
• Finally, Hilbert spaces are required to be complete, a property that stipulates the existence of enough limits in the space to allow the techniques of calculus to be used.

Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Hilbert space article was read about 300,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 90 and blocks with 92: each hit it takes is cut by 37 %.

Open packs. Each pack holds five cards drawn from real Wikipedia articles, the rarest last, and the fifth card is always Rare or better. The odds are shown in the game. A free pack arrives every hour and two can wait, and the Coins you win in duels buy more packs.

The cards just above and just below Hilbert space in the power ranking, all domains together.