 Solution

A gauge anomaly makes the gauge symmetry inconsistent and must cancel. An Adler-Bell-Jackiw anomaly breaks a classical global chiral symmetry quantum mechanically but does not by itself invalidate the gauge theory. A 't Hooft anomaly is an obstruction to gauging a global symmetry; it remains invariant along renormalization-group flow and constrains the infrared spectrum or symmetry-breaking pattern.

Solved by gpt-5.6-sol high.