Finding Nemo have renounced fish-eating diet. While at their progress meeting, Marlin discovers the diver's mask and notices an address written on it. However, Dory and Marlin fight over the mask, accidentally giving Dory a bloody nose. The blood sends Bruce into a relapsed feeding frenzy, and he attacks Marlin and Dory, who narrowly escape. Nemo is placed in a fish tank in a dentist's office, where he meets the "Tank Gang", a group of pet fish led by Gill. The gang learn Nemo is to be given to the dentist's niece Darla, who has killed previous fish given to her. Gill
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