Modal logic 1.5 - logical consequence in K

I discuss the notion of logical consequence, and outline two important approaches to consequence: the semantic/model-theoretic approach, and the syntactic/proof-theoretic approach. I focus on the system K, but it should be easy to see how the ideas can generalize to other systems.

[@tarirochihota8073]

Thank you! You have saved me from failing my logic paper. What my lecturer says is exactly parallel to what you say in your videos but you just articulate it such a straight-forward way that is clear and easy to follow. I am genuinely surprised I get it. I might just do well in this course after all.

[@m.evanwillis]

I wish I had had this video when I took my Symbolic Logic class years ago. This finally makes sense.

[@ffhashimi]

brilliant!
I was looking for this for a long time
thank you and keep the good job!

[@John77Doe]

There is an American guy who posted a better series of lessons and starts out with "Godel Escher Bach" examples, but right now I can't find his videos.

[@JulioCSilvaPhilosophy]

8:06 I think you should have said "syntactic consequence". Great video!

[@DrBump]

Brilliant!

[@user-co5og2ol4i]

You try to give the video more brightness it will be great if you do

[@LaureanoLuna]

4:40. Gamma is a set of sentences; a set cannot be made true: their members can.

[@Alkis05]

7:25 The counter example would be more clear with something like:
W = {w0,w1,w2}
w0Rw1, w1Rw2
aw1(p) = 1; aw2(p) = 0