A statement that contradicts itself, i.e., a statement that claims that the same thing is true and that it is false at the same time and in the same senses of the terms.
A logical inconsistency among two or more elements or propositions.
The act of contradicting.
A proposition that is false for all values of its propositional variables or Boolean atoms.
That which one is morally or legally obligated to do.
The state of being at work and responsible for or doing a particular task.
A tax placed on imports or exports; a tariff.
The efficiency of an engine, especially a steam pumping engine, as measured by work done by a certain quantity of fuel; usually, the number of pounds of water lifted one foot by one bushel of coal (94 lbs. old standard), or by 1 cwt. (112 lbs., England, or 100 lbs., United States).