Consider 1-D space. Let S and S' be two inertial reference frames. Let A and B be two events.
Co-ordinates of A and B under S are A = (xA,tA) and B = (xB,tB).
Let me define what I mean by when I say two events coincide - it simply means they have same space-time co-ordinates.
i.e. if (xA = xB) and (tA = tB), then w.r.t S, events A and B coincide.
I have two Qs:
Q1. Is my above definition of events that coincide correct?
Q2. If A and B coincide in S, then will the coincide in S' (i.e. two events being coincident is NOT a relative concept)