Quantifier Truth-Value Model Checker (2D)

Formal semantics defines the meaning of a sentence by its truth conditions: exactly the circumstances under which it is true. This 2D simulator builds a real model — a domain of flat individuals, each with its own color, shape and size — and lets you compose a quantified sentence from a quantifier (∀, ∃, ¬∃) and a predicate, then evaluates it against that model exactly the way Montague-style formal semantics does: by computing the predicate's extension and checking it against the domain. Satisfying individuals glow live on the canvas, and the panel tracks the extension's size, its share of the domain, and the resulting truth value as you change the sentence, the domain size, or randomize the model. Drag to pan the plane and scroll to zoom in on any cluster of individuals.