Finding Nemo devises a plan to escape: jam the tank's filter with a pebble so the dentist will have to put the fish in plastic bags to clean the tank, then roll out the window and into the harbor. Nemo attempts to jam the filter but fails, nearly dying in the process. The mask falls into a trench in the deep sea, where, while battling an anglerfish, Dory reads the address as "42 Wallaby Way, Sydney". To her own disbelief, Dory remembers the address despite her short-term memory loss. Dory and Marlin receive directions to Sydney from a school of moonfish. On
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