English

Noun

1. the inverse of the converse of a given proposition

Usage notes

From proposition, its inverse, its converse, and its contrapositive are derived as follows:

• Proposition: "If P then Q."
• Inverse: "If not P then not Q."
• Converse: "If Q then P."
• Contrapositive: "If not Q then not P."

A proposition and its contrapositive always have the same truth value, i.e. if one is true, so is the other, e.g.:

• Proposition: "If it's likely that someone would want to know what a term means, it passes WT:CFI|CFI." (true)
• Inverse: "If it's unlikely that someone would want to know what a term means, it fails WT:CFI|CFI." (not necessarily true)
• Converse: "If a term passes WT:CFI|CFI, it's likely that someone would want to know what it means." (not necessarily true)
• Contrapositive: "If a term fails WT:CFI|CFI, it's unlikely that someone would want to know what it means." (true)

See also

• converse
• inverse

vi:contrapositive zh:contrapositive