Q:

Is it better to write Integer or just Int?

We usually use Pascal in our school for programming, but in my personal life I prefer newer languages such as Python, C, or C++. All of these three languages use a data-type Int but Pascal uses Integer. It's actually the same but "Integer" is a little bit longer. Is writing something like this:
Type int=integer; a "good" or "bad" habit?

A:

I think in Pascal, it is bad habit, regardless of what one thinks about C or Cpp or whatever else, and whether int is good in those languages.
Redefining types in a language or in any way trying to create another language from Pascal or else is usually not a good idea. If you don't like Pascal, you should not use it, but if you redefine things, it will be harder and will take more time for Pascal programmers to understand or review your code.
Having said this, there are languages (like for instance Ruby) that allow creating very nice DSLs (domain specific languages), which are somewhat similar to the root of your problem if I understand correctly. If designed correctly, DSLs can indeed be very nice for specific problem domains.

A:

bad habit 
int is already a function in most Pascals, so that would not be wise. Even if this were not the case, I'd reserve it for external interfacing, in case an externally declared "int" type, OS or C compiler differs from the pascal language "integer".
And I also agree with Thilo. Adapt to the expected conventions, don't roll your own (even if based on major other languages). It will lead to a mixing of conventions which is worse than using either systematically.

