Solution
= 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.