Assertion: unnatural isomorphism | /r/HasProperty | \displaystyle =
Facets:
Source sentences:
text: Some authors distinguish notationally, using ≅ {\displaystyle \cong } for a natural isomorphism and ≈ {\displaystyle \approx } for an unnatural isomorphism, reserving = {\displaystyle =} for equality (usually equality of maps).