Marker's comments on Test 1 (Cook)

Students seemed over confident on this test.  Many handed in their
papers early, but did poorly.

Average Mark:  28/40

Quest 1:  Most students did well on this.

Quest 2:  Most students had the right idea, but some were wrong
in detail.  
Common mistakes:
**  Saying how TM M_0 behaves on input <M_i>, but forgetting that
the input to the machine is a description <M> without the i attached.
You should explain how to extract i from <M>.
**  Deciders M accept sets L(M), and do not necessarily compute
functions.

Quest 3:  Half the class wrongly claimed that the complement of A
is semidecidable.  This would be true if the definition
of A had the condition L(M) \subseteq PAL instead of L(M) = PAL.