Michaelmas Flashcards
What does Alethic mean?
Concerning possibility and necessity
What does decidable mean?
A formal language is decidable if there is an effective procedure to check if a sentence is logically valid in that language
What is an effective procedure?
A finite number of exact instructions that always terminates with the right answer in a finite number of steps
What does valid mean?
it is true on every assignment of truth values to the
atomic propositions
What does inconsistent mean?
it is false on every assignment of truth values to the atomic propositions.
When is a wff is satisfiable?
A wff is satisfiable if there is a model and world where it is true. A satisfiable
wff is also called consistent.
What is an evaluation function?
Give the semantics of possibility and necessity
On what frames is neccessary p implies p valid
Reflexive
Define reflexive
Define irreflexive
Define Serial
Define backwards linear
Define a pre order
Define an equivalence relation
State the axioms of K
Describe system T
Describe system D
Describe S4
Describe S5
Give an alternative description of S5
State which frame classes relate to which axiom
Define the modal evaluation game
Give the key lemma for the modal evaluation game
Define a bisimulation
Define a tree unravelling
Define modal depth
Define Chop
Give the effective procedure for checking validity
