moved lemmas for orderings and lattices on predicates to corresponding theories, retaining declaration order of classical rules; tuned headings; tuned syntax
structure ROOT =
struct
structure Codegen =
struct
fun lookup ((k, v) :: xs) l =
(if ((k : string) = l) then SOME v else lookup xs l)
| lookup [] l = NONE;
end; (*struct Codegen*)
end; (*struct ROOT*)