FARZANEGI
درونشد
هموندی
Encyclopedia
Philosophy
Logic
Mathematics
Computing
Ontology
Persian Translator
Logic Lab
Hall of Fame
Library
Dictionary
About
PL.FL.03
دیسهای
(¬𝐴⊃¬𝐵)⊃(𝐵⊃𝐴)
(¬A⊃¬B)⊃(B⊃A)