Page "First-order logic" Paragraph 21

Here Person ( x ) is interpreted to mean x is a person, Time ( y ) to mean that y is a moment of time, and Canfool ( x, y ) to mean that ( person ) x can be fooled at ( time ) y.

For clarity, this statement asserts that there is at least one person who can be fooled at all times, which is stronger than asserting that at all times at least one person exists who can be fooled.

This would be expressed as: