how to enumerate/generate all possible binary trees from N leaves and N-1 nodes?

I am trying to implement the 24 Game in ansi C. This game goes as follows:

how to enumerate/generate all possible binary trees from N leaves and N-1 nodes?

I am trying to implement the 24 Game in ansi C. This game goes as follows:

What do you get when you cross a multi-precision integer with a floating-point number?

I’m working on adding multi-precision integers to the suite of numeric types in my APL interpreter, but I’m not sure what to do about the odd type-combinations that now arise. I now have the following types: