sheet 4 pblm:3

Question

for below question

i got answers:

(p&!a&!q)|(!p&q&!a)|(!p&!a&!q)|(!p&a&!q) --dead states

(p&a&!q)|(p&q&!a)|(p&a&q)|(p&!a&!q)      -initial states

(p&a&!q)|(!p&q&a)|(p&q&!a)|(p&a&q) --reachable node

but in tool its showing as wrong solution .can some help me like how to do.how  can  we check in teaching tool whether solution is wrong or correct

Answer 1

Read your deadend states again. I think one of the four states you listed should be a different one.

For the initial states, try to remove the deadend states.

Try to recompute them with the updated deadend states.

Comments

thank you i will recompute

Answer 2

The last dead-end-state is wrong. It should be (p&!a&q) instead of (!p&a&!q) since you can't go anywhere with !a from {p,q}.

As for you initial states, you need to remove all dead-end states from your list of initial states. Therefore you should only have the initial states p&!q&a and p&q&q since p&q&!a and p&!a&!q are dead-ends.

Then you need to reconsider your list of reachable notes with the corrected information about initial and dead-end states.

Comments

thanks. (p&a&!q)|(!p&q&a)|(p&q&!a)|(p&a&q)  (is initial states are by default reachable node

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According to the definition used in the exercise presentations, not all initial states are reachable: see https://q2a.cs.uni-kl.de/686/arent-all-initial-states-by-default-reachable

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The reachable states then should be:
p&!q&a
!p&q&a
!p&q&!a
p&q&a
p&q&!a