setup and hold time check for different overlapping clock cases

[deepen talati]

Hello sir. I am reading about lockup latches. Sir how exactly lockup cell removes the hold violation? And sir why we do check setup analysis in next clock and not at the same clock? If first clock for destination clock laging the source clock and during that time if data can settle then what will be happen? And why we are not using lockup latches for non overlapping clocks? Waiting for your reply sir.