In the impulse article on Wikipedia, the mathematical derivation chapter: $$J = \int_{t_1}^{t_2} \frac{d\mathbf{p}}{dt}\, dt = \int_{p_1}^{p_2} d\mathbf{p} = \mathbf{p_2} - \mathbf{p_1} = \Delta \mathbf{p}$$
As someone noticed in the article's Talk:
After the "therefore" statement in the "Mathematical derivation in the case of an object of constant mass" section, a misuse of notation is used to seemingly "cancel out" the 'dt's in the integration expression,. This should instead be a statement of the Second Fundamental Theorem of Calculus to derive the impulse-momentum theorem. While the "cancelling" is a subtlety that provides the correct results, it could mislead readers. A change could look like $$I = \int_{t_1}^{t_2} \frac{d\mathbf{p}}{dt}\, dt = \mathbf{p_2} - \mathbf{p_1} = \Delta \mathbf{p}$$
Which notation is correct here?
