Primary or focal hyperhidrosis may be further divided by the area affected, for instance palmoplantar hyperhidrosis (symptomatic sweating of only the hands or feet) or gustatory hyperhidrosis (sweating of the face or chest a few moments after eating certain foods).
The proverb The proof of the pudding is in the eating dates back to at least the 14th century. 1  The phrase is widely attributed to the Spanish author Cervantes in his novel The Ingenious Gentleman Don Quixote. The phrase is often incorrectly stated as the proof is in the pudding..
In proof by contradiction (also known as reductio ad absurdum, Latin for by reduction to the absurd), it is shown that if some statement were true, a logical contradiction occurs, hence the statement must be false. A famous example of proof by contradiction shows that is an irrational number :