Some prolog to manipulate types and type relations from various pokemon games.

Currently, Gen1 (Red/Blue/Yellow) types are implemented, in pokemon1.pl. I will eventually define Gen2 (Gold/Silver) in pokemon2.pl.

Results of running the prolog are in perfect1.csv, triangles1.csv, and loose1.csv.

I have defined three types of type triangles as follows:

• A perfect triangle (A, B, C) means that types are strong (double or quadruple damage) when read left to right, and weak (half or quarter damage) when read right to left. It is assumed there is a link between C and A, so that C is strong against A, and A is weak against C.

• A loose triangle (A, B, C) requires either (A strong vs. B) or (B weak vs. A). The other two relationships behave similarly.

• A triangle (A, B, C) requires only that each type is strong vs. the next type, when read right to left.

Additionally, I have defined how to handle compound types, such as "Dragon, Flying". A type B is strong vs. a compound type (C1, C2) if B is strong vs. one of C1 or C2, and not weak vs. the other. A similar definition exists for B being weak to (C1, C2).

In order for a type triangle with compound types to exist, we must also define (C1, C2) being strong/weak to B. Since the first type is supposed to represent an attack type, we can say that (C1, C2) is strong vs. B if either C1 or C2 is strong vs. B. For now, I have defined that (C1, C2) is weak vs B if either C1 or C2 is weak to B. Both of these definitions are somewhat arbitrary, but without them, you can't have a type triangle.