Differential Equations

[Angus]

When entering an expression like the example above I have inconsistent entry behaviour. After hitting the colon inside the square brackets, the colon is not displayed in the expression. It is just displayed as a 'vector' which I would consider less readable and, yes, I was confused first. Surprisingly the format is converted to exactly the given example once confirmed. Strange and not quite understandable for me. Can someone explain why expressions are differently displayed and entered in one same app? Not talking globally, considereing the macrocosmos of home and cas.