These mathematical objects were synthesized by Martin Davis with Emil Post's model, resulting in a particularly simple Post- version of them. One of these was the basis for the ACE, which appeared a decade after they were introduced to provide a diagonal solution to the Entscheidungsproblem in "On Computable Numbers." The set of these is isomorphic to the set of procedures in lambda calculus according to a thesis named for the inventor of lambda calculus and for the namesake of these devices. Every computable algorithm 
These mathematical objects were synthesized by Martin Davis with Emil Post's model, resulting in a particularly simple Post- version of them. One of these was the basis for the ACE, which appeared a decade after they were introduced to provide a diagonal solution to the Entscheidungsproblem in "On Computable Numbers." The set of these is isomorphic to the set of procedures in lambda calculus according to a thesis named for the inventor of lambda calculus and for the namesake of these devices. Every computable algorithm corresponds to one of these objects, which has a several-instruction read/write head and infinite tape. For 10 points, name these model computers named for a British computer science pioneer.
These mathematical objects were synthesized by Martin Davis with Emil Post's model, resulting in a particularly simple Post- version of them.
{Turing machine}s