# How to model transition probability if action does not lead to a state change (in MDP)?

An MDP (markov decision process) is defined as a set of states $$S$$, actions space $$A$$, Transition Probabilities $$T$$ and Rewards $$R$$. An action $$a$$ in a state $$s$$ usually result in a change of state and the probability is defined as $$p(s'|s,a)$$. I have a question if an action $$a$$ in a state $$s$$ does not result in a change of state then how to define transition probabilities $$p(s'|s)$$? How to define state transitions from $$s$$ to $$s'$$ when state transitions do not occur after taking an action $$a$$ in a state $$s$$?

$$P(s' = U | s = V, a) = \mathbf{1}(U = V)$$