Part II: Using either the method of truth tables or the method of truth trees, determine whether the following argument forms are deductively valid or invalid. Be sure to include all of your justifications when you use truth trees - failure to include you justifications (i.e. rule and lines rule as applied to) will result in no points for the problem. Make sure you say whether the table or tree shows the argument to be valid or invalid (and why). 9. A (B v C), B = (-C v D), -D5C :: A=D