Finding Nemo installs a new high-tech filter before the Tank Gang can escape. Marlin and Dory exit the East Australian Current and are engulfed by a blue whale. Dory communicates with the whale, which carries them to Sydney Harbour and expels them through his blowhole. They meet Nigel, who helps the pair escape from a flock of relentless seagulls and takes them to the dentist's office. Darla has just arrived, and the dentist is handing Nemo to her. Nemo plays dead to save himself as Nigel arrives, terrifying Darla and throwing the office into chaos. After Nigel is violently thrown out by
Forgetful functor of formal logic, a functor of the first kind removes axioms. The second kind removes predicates. The third kind remove types. An example of the first kind is the forgetful functor Ab → Grp. One of the second kind is the forgetful functor Ab → Set. A functor of the third kind is the functor Mod → Ab, where Mod is the fibred category of all modules over arbitrary rings. To see this, just choose a ring homomorphism between the underlying rings that does not change the ring action. Under the forgetful functor, this morphism yields the identity. Note that