PWPP ⊆ PPP Inclusion · folklore Statement Weak Pigeon reduces to Pigeon, so PWPP ⊆ PPP — folklore. Sketch Given C:{0,1}n→{0,1}n−1, let C′(x):=1∥C(x), a map {0,1}n→{0,1}n that never outputs 0n; every Pigeon solution for C′ is a collision of C′, hence of C.