The weather is good today.
John will go to the cinema if and only if Jack goes to the cinema today. Jack will go to the cinema if and only if Iron Man is on and the weather is not bad today. Some days in March have bad weather. Iron man is on. It's March now.
GoToTheCinema(john, today) ↔ GoToTheCinema(jack, today) GoToTheCinema(jack, today) ↔ (Movie(ironman) ∧ ¬BadWeather(today)) ∃x (Month(march) → BadWeather(x)) Movie(ironman) Month(march)