Dear members,

I had written this following question in the thread Introduce Yourself, I realized it, so I present the question here:

I would like to ask a question quickly, in case some member can answer it.

The question is:

How do I write mathematically the following idea or sutuation:

There is a line from the point A to the point B (a --->b)

then another line 45 degrees (in relation to the x axes) right from the point B to the point C (b---->c)

and then 45 degrees left (in relation to the x axes) from the point C to the point D (c --->d)

Would it be correct to write this as:

a--->b:b--->c:c--->d for example?

What I want to know is how to represent mathematically two points which have exactly the same coordinates.

Thank you by advance.