When it comes to pronouncing the symbol “∈”, there are different conventions and preferences among mathematicians. Personally, I tend to follow the suggestion of Paul Halmos, a well-known mathematician, who expressed his preference for reading “∈” as “is in” rather than simply as the preposition “in”.
Let me explain further. In set theory, the symbol “∈” is used to indicate that an element belongs to a particular set. For example, if we have a set A containing the elements 1, 2, and 3, we would write 1 ∈ A to indicate that 1 is an element of set A.
Now, in terms of pronunciation, some mathematicians may choose to read “∈” as “be an element of”, emphasizing the concept of being an element. However, Halmos favored the more concise and natural-sounding phrase “is in”. This pronunciation choice aligns with everyday language and makes mathematical statements easier to read and understand.
To illustrate with an example, instead of saying “x is an element of set A”, Halmos would suggest saying “x is in set A”. This subtle change in wording makes mathematical expressions more accessible and less formal, without sacrificing clarity or accuracy.
It is important to note that these pronunciation preferences may vary among mathematicians, and there is no one “correct” way to pronounce mathematical symbols. However, Halmos’ suggestion of reading “∈” as “is in” has gained popularity and is widely accepted.
When encountering the symbol “∈” in mathematics, you can choose to pronounce it as “is in” to convey the notion of an element belonging to a set. This pronunciation choice adds a touch of informality and makes mathematical expressions more approachable.