Problem 1.12

This problem took me about a week.
The pascal function displays a pretty triangle when called. You must
call up to which row you want to see. For example , if you want a
triangle up to row 2, you type (pascal 2 2)
The recursion part , function f, took me about 5 minutes.

I'm not sure why I wanted to create a pretty triangle, but
now that it is a pretty triangle, well, it's a pretty triangle.

Current, 5-6% finished with the book, back to working on it now.