This tool analyzes a collection of sentences in Relational Logic. At this point, the language is restricted to one binary relation constant (p) and four object constants (1, 2, 3, 4). 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.