Another indicator of the presence of medical waste, which may be used instead of or in addition to the red or orange color code, is the BIOHAZARD symbol. Medical waste from health care facilities must be treated in a way that destroys its potential for causing disease, prior to disposing it in a landfill.
In classical logic disjunctive syllogism (historically known as modus tollendo ponens) is a valid argument form which is a syllogism having a disjunctive statement for one of its premises.
Logical disjunction is an operation on two logical values, typically the values of two propositions, that has a value of false if and only if both of its operands are false. More generally, a disjunction is a logical formula that can have one or more literals separated only by ORs.