Singular Propositions, Negation and the Square of Opposition

This paper contains two traditions of diagrammatic studies namely one, the Euler-Venn-Peirce diagram and the other, following tradition of Aristotle, the square of oppositions. We put together both the traditions to study representations of singular propositions (through a diagram system Venn-i, involving constants), their negations and the inter relationship between the two. Along with classical negation we have incorporated negation of another kind viz. absence (taking a cue from the notion of 'abhava' existing in ancient Indian knowledge system). We have also considered the changes that take place in the context of open universe.