justified
truth
vacuous truth
logical truth
truth
verificationism
Russell
Russellian
monk
A Solution of the Decision Problem for the Lewis systems S2 and S4, with an Application to Topology
computing
first order
Necessitation rule
Generalization
Admissible rule
structural rules
rules of derivation
sequent
Raham Asha
Ruth Barcan Marcus
Rudolf Carnap
journalism
Explication
A Critical Exposition of the Philosophy of Leibniz
Ronald Rivest
approach
Raymond M. Smullyan
Stoic
Mathematics
Tractatus Logico-Philosophicus
consequence relation