FM Thesis

Slow weekend for research. I spent all weekend visiting my in-laws, so the only thing I managed to get done was to finish chapter 8 of Using Z. That was the one on functions.

Maybe I'm just getting rusty, but this chapter was a little confusing. It covered lambda notation (which I think I get), functions on relations (which I also think I get, though the examples were a little confusing), function overriding (which seems pretty basic), properties of functions, and finite sets. It got really confusing in the properties of functions chapter when they introduced different styles of arrows to denote different types of functions. So injective functions got one style of arrow, surjective another, and bijective yet another. Plus there was a vertical line through the arrow to denote partial functions and, later, a double line to indicate the set of all finite functions on two sets. I think I'm going to have to go back and make myself a cheat-sheet of all the symbols I've seen in the past few chapters.