Modus vivendi Modus vivendi Modus vivendi is a Latin phrase that means "mode of living" or “way of life”. It often is used to mean an arrangement or agreement that allows conflicting parties to coexist in peace. In science it is used to describe lifestyles. "Modus" means "mode", "way", "method", or "manner". "Vivendi" means "of living". The phrase is often used to describe informal and temporary arrangements in political affairs. For example, if two sides reach a "modus vivendi" regarding disputed territories, despite political, historical or cultural incompatibilities, an accommodation of their respective differences is established for the sake of contingency. In
Modus tollens case that Q" (or in brief "not Q"). Then, whenever "formula_6" and "formula_9" each appear by themselves as a line of a proof, then "formula_10" can validly be placed on a subsequent line. The history of the inference rule "modus tollens" goes back to antiquity. "Modus tollens" is closely related to "modus ponens". There are two similar, but invalid, forms of argument: affirming the consequent and denying the antecedent. See also contraposition and proof by contrapositive. The first to explicitly describe the argument form "modus tollens" was Theophrastus. The "modus tollens" rule may be written in sequent notation: where formula_12