Exercises in COMPLEX TRUTH TREES - Logic

[@DaiMoscv]

I'm really starting to like these logic threes, feels like a puzzle game xD

[@T-The-K]

Had the first one perfectly but messed up with the second one, makes complete sense now though so i'm good. I wish there was some sort of randomizer site where i could solve truth trees.

[@paulcarello6390]

Exercise 1 1. ~[P ∧ ~(~Q ∨ R)] 2. P ∧ ~(~Q ∨ R) By inspection, 1 and 2 are contradictory hence statements are inconsistent.

[@emmanuelarce2131]

In the 2nd exercise, could the ultimate branch be closed in the line 11 because it's a contradiction of the line six?

[@nitishgautam5728]

Yes , obviously it's about your logic , we don't rely on faith or remembering things blindly... Accepting methods are correct without logical thinking.

[@FlexThoseMuscles]

w000t mure examples :D

[@jalalbouzid2641]

Hey, in the first exercise. You could have solved it quicker and easier if you were to decompose "1" right after line "4"; in that case you would have gotten a branching of " Not P" and " Not not(not Q or R)... which becomes simply ( not Q or R)". And then you have before "P" and you have " "Not ( not Qor R)" which is in general a contradiction of (not Q or R )"; hence both braching are gonna close in only 6 lines instead of 10. Please correct me if I am wrong!