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 partition_pigeonhole P D A :
partition P D -> #|P| <= #|A| -> A \subset D -> {in P, forall B, #|A :&: B| <= 1} ->
{in P, forall B, A :&: B != set0}.