A First Class Constraint Generates Not a Gauge Transformation, But a (Bad) Physical Change: The Cases of Maxwell and GR

A project in recovery of Anderson and Bergmann that were clear in the 50s but lost since. Question whether first-class constraints can do their work in isolation, or rather they must work as a team. Idea will be that, for example, change is not lost in GR when we understand better the connection between gauge transformations and first class constraints.