Question

Hi, this question is from Theory of Computation. Kindly help if you can.

Exercise 1 Define a language L to be co-NP-complete if it is in co-NP and a languages in co-NP can be polynomial-time reduced to L. Say that a formula of quantified boolean logic is a universal sentence if it is a sentence (i.e., has no free variables) of the form Vai... Vxn(V) where> is a propositional logic formula (contains no quantifiers). Show that the language to I is a true universal sentence) is co-NP-complete. (Hint: use the fact that SAT is NP-complete.)

Answer 1

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