Section StrongRelaxedInjections.
Admitted.

Lemma memval_inject_strong_compose:
forall (j12 j23 : meminj) (x1 x2 x3 : memval),
memval_inject_strong j12 x1 x2 ->
memval_inject j23 x2 x3 -> memval_inject (compose_meminj j12 j23) x1 x3.