Answer
a) The machine halts (and accepts) at the blank following the input, having changed the tape from 11 to 01.
b) The machine changes every other occurrence of a 1, if any, starting with the first, to a 0, and otherwise leaves the string unchanged; it halts (and accepts) when it comes to the end of the string.
Work Step by Step
Telling What does the Turing machine described by the fivetuples
(s0, 0, s0, 0,R), (s0, 1, s1, 0,R), (s0,B, s2,B,R), (s1, 0, s1, 0,R), (s1, 1, s0, 1,R), and (s1,B, s2,B,R) do when given
a) 11 as input
...... The machine halts (and accepts) at the blank following the input, having changed the tape from 11 to 01.
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b) an arbitrary bit string as input
.......The machine changes every other occurrence of a 1, if any, starting with the first, to a 0, and otherwise leaves the string unchanged; it halts (and accepts) when it comes to the end of the string.
