When does the solver consider the system 'solved' for a given `t` ?

[twitchyliquid64]

Sorry if this is a dumb question to anyone in the field! Just didnt see it in the documentation anywhere.

Is the solution to a System for a given timestep just when dy ~= 0? i.e. root-finding?

If not, how does the solver know when its done with a particular integration step and its okay to do the next one?