Section Safety.
Context (ST:Type)(SCH:Type).
Context (STEP:ST->SCH->ST->SCH-> Prop).
Context (valid: ST-> SCH -> Prop).
Hypothesis em: forall P, P \/ ~ P.

Corollary SsafeN_ksafe: forall n st,
SsafeN n (@P_init st) -> forall U, valid st U -> ksafe st U n.