# What does this symbol signify ('\Game' in mathcha.io editor)?

While playing around in an online LaTex-like editor (mathcha.io) I came across the following symbol, entered with '\Game': Can anyone tell me what it signifies? All my online searches came up short on this one.

In descriptive set theory, $$\Game$$ is the game quantifier - taking $$f$$ to be a variable ranging over infinite sequences of natural numbers, "$$\Game f(\varphi(f))$$" means "Player $$1$$ wins in the game where players $$1$$ and $$2$$ alternate playing natural numbers and player $$1$$ wins iff $$\varphi$$ holds of the resulting infinite sequence." So for example, if $$\varphi$$ is "is eventually periodic," it's easy to show that $$\neg\Game f(\varphi(f))$$ - one way for player $$2$$ to win the relevant game is to just make sure that they always play a number larger than any number which has occurred so far.
(Note that making $$\varphi$$ weaker only makes it easier for player $$1$$ to win, so $$\Game$$ is a monotonic quantifier - like $$\exists$$ and $$\forall$$, and unlike something such as "finitely many" or "an even number of.")