Exam 12: Models of Computation

If we post a program and try to construct a Turing machine to solve it but are not successful, does this prove that no Turing machine exists? If not, why would prove this?

Given that we can make a comparison between two Turing machine algorithms for the same task, can we compare the efficiency of a Turing machine algorithm with one that runs on a "real" computer?

The equation for the distance d that a moving vehicle travels - the product of rate r and time t - is considered to be a model.

The real value of Turing machines as models of computability is in exposing problems that are ____________________.

According to its definition, what must an algorithm be or do?

At any point in time, only a finite number of cells in the Turing machine input contain ____ symbols.

We can write a Turing machine to add 1 to any number; such a machine is often called a(n) ____.

Every problem has an algorithmic solution.

One consequence of a(n) ____________________ problem related to the halting problem is that no program can be written to decide whether any given program always stops eventually, no matter what the input.