I've been waiting for key lime pie all week
Antecedent: Deprived of key lime pie all week, walk past the pie store and see key lime pie
Behaviour: Ask the employee for key lime pie
Consequence: Get key lime pie (positive reinforcement)
The context in this situation is that I have not had key lime pie from the pie place downstairs in a week. Even though I walk past the pie store everyday, my motivation for key lime pie needed to be high in order for me to go in this time. Motivation (a.k.a. motivating operations) comes into play as an antecedent to our behaviour.