 Shin’s work alters Peirce’s modifications of Venn diagrams to achieve an increase in expressive power without such a severe loss of visual clarity. This revision is made in two stages: (i) Venn-I: retains Venn’s shadings (for emptiness), Peirce’s ‘x’ (for existential import) and Peirce’s connecting line between ‘x’s (for disjunctive information). (ii) Venn-II: This system, which is proven to be logically equivalent to monadic predicate logic, is the same as Venn-I except that a connecting line between diagrams is newly introduced to display disjunctive information.