This tool analyzes a collection of sentences in Relational Logic. At this point, the language is restricted to four object constants (1, 2, 3, 4) and one unary relation constant (p) or two unary relation constants (p and q) orone binary relation constant (r). Usage: Enter sentences in the text box and press Evaluate. The tool will indicate whether the sentences are valid, contingent, or unsatisfiable. In the case of a contingent set of sentences, the tool will also show one interpretation that makes the sentences true and one interpretation that makes the sentences false.