Headaches are one effect that can come from inhalation of isopropyl alcohol. Isopropyl alcohol, or rubbing alcohol, is often used in the home or in medical facilities to treat various conditions or to sterilize instruments and skin. However, if isopropyl alcohol is inhaled there can be serious side effects.
1a) Definition of contradiction: A contradiction exists any time a proposition P is asserted to be true in conjunction with its negation, not-P. 1b) Definition of conjunction: A conjunction is a connective that joins two propositions.
For a concise description of the symbols used in this notation, see List of logic symbols. In classical logic, the law of non-contradiction (LNC) (or the law of contradiction (PM) or the principle of non-contradiction (PNC), or the principle of contradiction) is the second of the three classic laws of thought.