fact: Definition pre_bisim_pullback_structure (S1 S2 S3:F_coalgebra) R12 R23: is_F_bisimulation _ _ R12 -> is_F_bisimulation _ _ R23 -> weak_pullback_Rel S1 S2 S3 R12 R23 -> let RS12:={s1s2 : states S1 * states S2 | R12 (fst s1s2) (snd s1s2)} in let RS23:={s2s3 : states S2 * states S3 | R23 (fst s2s3) (snd s2s3)} in let r2:=fun r:RS12 => (snd (proj1_sig r)) in let r3:=fun r:RS23 => (fst (proj1_sig r)) in weak_pullback _ _ _ (lift_F_ _ _ r2) (lift_F_ _ _ r3).
imports: ExtensionalFunctor Setoid