- When you say “X is Y”
- One interpretation is “X=Y.”
- Since this is a symmetric relation, “Y=X” also holds.
- Sometimes it doesn’t work.
- Hanako is the elephant, but the elephant is not Hanako.”
- 「」X⊂Y
- X is a subset of Y
- From thinking of X and Y implicitly as dots to thinking of them as sets
- It is also expressed as “is-a relationship…”
- Is it not a bias as if X is [individual (in philosophy)
- In general, X is not limited to individual objects.
- For example, “An integer is a rational number.
- Every integer is a rational-number.
- The is-a relation, which assumes that X is an individual, does not fit when a set comes to X, so it is converted to an individual with Every.
- Other conversions such as X is a kind of Y. are also seen.
This page is auto-translated from /nishio/「は」は「＝」だけでなく「⊂」 using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I’m very happy to spread my thought to non-Japanese readers.