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I'm lost on this example problem. My professor did not explain it very well and the book is no help either. Any help would be appreciated. Here goes:

For each of the following cases, you are given a set of prepositional logic statements that is true. Using resolution, determine which of the individual statement is true or not.

Example (A OR NOT B), (A OR NOT C), (C OR D), (A OR NOT D) – by resolution, you can show that A must be true (but nothing about B, C, D individually)

a. (A OR B OR C), (NOT A OR NOT B), (NOT C OR NOT D)

b. (NOT A OR B), (C OR NOT D), (NOT C OR NOT D), (A OR B OR D)

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    No answer yet.. so meanwhile, I will try to recall resolution. You have a set of statements $S$ (in specific format: clauses). Pick two statements at a time from $S.$ The two statements should be the form $a \lor \lnot b, c \lor \lnot b.$ Produce a new statement $a \lor c,$ where $b$ is eliminated. This step is called resolution step. Add the new statement to $S.$ Repeat until you can show the goal statement or can not resolve more.2012-03-20
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    @J.D. Shouldn't $b$ have different polarities in the two original clauses?2012-03-21
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    @HenningMakholm Indeed. It's a mistake. Thanks. Penn, I meant resolve $a \lor b$ with $c \lor \lnot b$ to get $a \lor c.$2012-03-21

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