A "projective" mapping is a finite sequence of perspective mappings. Complex member variables for contracts including arbitrarily hierarchical mappings and structs were supported. Higher order polynomial mappings are common, especially quadratic. Now we consider the composition of two linear mappings between finite dimensional vector spaces. Such mappings are surjective but not injective. This concept is very useful for iterated function systems where contraction mappings are often used. Steinhaus theorem that the linear mappings are uniformly bounded by some constant . The page table must supply different virtual memory mappings for the two processes. Users can execute complex commands with "key mappings," which can be customized and extended. These address mappings are for backwards compatibility. As with all link-layer mappings of IP, RFC4944 provides a number of functions. Numbers, strings, sequences, and mappings can all be compared. The composite of two monotone mappings is also monotone. Collections come in two basic forms&colon; "sequences" and "mappings". Common Lisp provides the codice 27 class for efficient mappings.