subject
Algebraic structure
Data structures
Lewis's system S1
Lewis's system S2
Modal System S3
Formal System
quantified modal system
Routley Star
Stoic
rigour
austerely
species
fatalism
hobby
vanish identically
Critique of Pure Reason
tortoise
three-valued
sentence
Common Sense
Saul Kripke
obversion
assertion
assertoric
Socrates
dog
C. S. Peirce
quantifier