Logic Lecture: Introduction to Modal Logic - 3

[bcal86]

Thank you for all you've done



[LaureanoLuna]

P is necessary iff the negation of this possibility is not required, etc. is not correct.

There is a number of readings of the formulae here and in lesson 2 that should be revised. For instance, '~P' cannot be read 'P does not exist'. P is supposed to be a proposition and ~P its negation, not its nonexistence.

[arahim91]

@LaureanoLuna when learning modal logic you gotta start slow. As people become proficient in it, and the lectures become more adept, i think he'll revise it. But you're right about (not)P not necessarily implying nonexistent.