Given a Turing machine

M

, consider the following language

L

LEFT

=

{

(

M

,x

)

|

M

moves its head to the left at least once during its execution on input

x

}

.

Describe a Turing machine that decides this language.

E 2. Given a Turing machine M, consider the following language LLEFT-(M),) M moves its head to the left at least once during its execution on input z. Describe a Turing machine that decides this language