aqua regia

kuningasvesi puhekieltä A mixture of three parts concentrated hydrochloric acid to one part concentrated nitric acid.
2005, D.J. Krus, http://www.docstoc.com/docs/82427586/Elements-of-Propositional-Calculus Elements of Propositional Calculus

Consider another example. 'If gold is placed in aqua regia then it dissolves.' Aqua regia is a mixture of nitric and hydrochloric acids that dissolves gold or platinum. Observation of gold dissolving in aqua regia (argument 1 1) lends credence to the above conditional statement.Not placing the gold into aqua regia and gold not dissolving (argument 0 0) does not disprove the truth-value of this conditional.