Valid Argument/Examples/Trout have Wings

Example of Valid Argument
The following is a valid argument with false premises:


 * All trout are mammals.
 * All mammals have wings.


 * Therefore all trout have wings.

Proof
This is a categorical syllogism of the first figure, of the form $AAA$.

From Valid Patterns of Categorical Syllogism, this is seen to be a valid argument.

The premises, however, are false.

It follows that the argument, while valid, is unsound.