a particular way or method of doing something

every killer has his own special modus operandi

the rule of logic which states that if a conditional statement (‘if p then q’) is accepted, and the antecedent (p) holds, then the consequent (q) may be inferred

the rule of logic which states that if a conditional statement (‘if p then q’) is accepted, and the consequent does not hold (not-q) then the negation of the antecedent (not-p) can be inferred

an arrangement or agreement allowing conflicting parties to coexist peacefully, either indefinitely or until a final settlement is reached

the two states have with difficulty reached a modus vivendi, though hardly friendship