Section BigSetOps.
Variables T I : finType.
Implicit Types (U : {pred T}) (P : pred I) (A B : {set I}) (F :  I -> {set T}).
End Curry.

Lemma partitionU1 P D B :
partition P D -> B != set0 -> [disjoint B & D] -> partition (B |: P) (B :|: D).