  We use the notion of collapse of generalized indiscernible sequences to
classify various model theoretic dividing lines. In particular, we use collapse
of n-multi-order indiscernibles to characterize op-dimension n; collapse of
function-space indiscernibles (i.e. parameterized equivalence relations) to
characterize rosy theories; and finally, convex equivalence relation
indiscernibles to characterize NTP2 theories.
