SOLUTION: I need to make a truth table for this. Is this argument valid or invalid? [Nv-(NvP)]→-R, P ├ R

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Question 980136: I need to make a truth table for this. Is this argument valid or invalid?
[Nv-(NvP)]→-R, P ├ R
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
The premises are the columns marked in light blue. The conclusion is the last column.



Notice how the second row and the sixth row have

premise [N v ~(N v P)] -> ~R being true (T)
premise P being true (T)
conclusion R being false (F)

These rows have all premises true with a false conclusion. So this means that the argument is invalid