Question

Write minimal negations for the following statements. (In other words, if the statement below is P, what would ¬P mean?) a) Everybody was kung-fu fighting for at least 10 hours. b) There is a river with at least two tributarie

Answer 1

a) Somebody was kung-fu fighting for less than 10 hours.

b) All rivers have less than two tributaries.

Explanation:

To write minimal negation statements, one must abide by the following rules:

1. If all Xs are Y ⇒ There is one X that is not Y

2. If one X has Y⇒ All Xs do not have Y

a) "Everybody was kung-fu fighting for at least 10 hours"

Following the first rule:

Somebody was kung-fu fighting for less than 10 hours.

b) "There is a river with at least two tributaries"

Following the second rule:

All rivers have less than two tributaries.