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WikiCards · Card list · Science cards · Open set
Uncommon card · Science
Open set, an Uncommon card
In general topology and mathematical analysis, an open set is a generalization of an open interval in the real line.
- Rarity
- Uncommon
- Domain
- Science
- ATK
- 68
- DEF
- 49
- Power
- 117
- Wikipedia reads a year
- 59,000
Power 117 (ATK + DEF): stronger than 65 % of WikiCards cards.
Open set quiz: 3 questions
Three questions on the Open set card, the way WikiCards duels ask them. Pick an answer, the facts are just below.
Find the missing word
A set in which such a collection is given is called a ______ space, and the collection is called a topology.
Answer
topological. A set in which such a collection is given is called a topological space, and the collection is called a topology. From the Open set article on Wikipedia.
Which of these cards hits hardest (highest ATK)?
Answer
Gaussian quadrature. Gaussian quadrature 74 · Bus 71 · Open set 68 · Sinus tachycardia 61 ATK in WikiCards.
Which of these Wikipedia articles is read the most in a year?
Answer
Imaginary unit. Imaginary unit 130,000 · Bus 90,000 · Open set 59,000 · List of awards and nominations received by Laura Linney 46,000 Wikipedia reads over a year.
In a duel, each round asks a question like these about the opposing card, with 15 seconds to answer.
The facts on the card
The card carries these facts from its Wikipedia article.
- In a metric space, an open set is a set that, with every point P in it, contains all points of the metric space that are sufficiently near to P.
- More generally, an open set is a member of a given collection of subsets of a given set, a collection that has the property of containing every union of its members, every finite intersection of its members, the empty set, and the whole set itself.
- A set in which such a collection is given is called a topological space, and the collection is called a topology.
Why it is Uncommon
Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Open set article was read about 59,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 68 and blocks with 49: each hit it takes is cut by 20 %.
How to get Open set
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.
More Science cards
Cards close in power
The cards just above and just below Open set in the power ranking, all domains together.
- Symphony No. 5Uncommon · Arts · ATK 66 DEF 51
- Winchester '73Uncommon · Arts · ATK 64 DEF 53
- Electrical wiringUncommon · History · ATK 70 DEF 47
- AsthenosphereUncommon · Science · ATK 64 DEF 53
- Art historyUncommon · Science · ATK 70 DEF 47
- Montgolfier brothersUncommon · Society · ATK 63 DEF 54
Card lists
- Wikipedia quizNew questions every day
- All cards from A to ZEvery card, by name
- Science cards
- Legendary cards
- Tier listS and A tiers by power (ATK + DEF)
Credits
Text : Wikipedia, Open set (revision), CC BY-SA 4.0. Photo : Richard Giuly at English Wikipedia, Public domain, Wikimedia Commons.
