"In order to translate a sentence from English into French two things are necessary.
First, we must understand thoroughly the English sentence. Second, we must be familiar with the forms of expression peculiar to the French language.
The situation is very similar when we attempt to express in mathematical symbols a condition proposed in words. First, we must understand thoroughly the condition. Second, we must be familiar with the forms of mathematical expression.
George Polya"
George Polya"