(* Title: HOLCF/ssum3.thy
ID: $Id$
Author: Franz Regensburger
Class instance of ++ for class pcpo
*)
Ssum3 = Ssum2 +
instance "++" :: (pcpo,pcpo)pcpo (least_ssum,cpo_ssum)
consts
sinl :: "'a -> ('a++'b)"
sinr :: "'b -> ('a++'b)"
sscase :: "('a->'c)->('b->'c)->('a ++ 'b)-> 'c"
defs
sinl_def "sinl == (LAM x. Isinl(x))"
sinr_def "sinr == (LAM x. Isinr(x))"
sscase_def "sscase == (LAM f g s. Iwhen(f)(g)(s))"
translations
"case s of sinl$x => t1 | sinr$y => t2" == "sscase$(LAM x. t1)$(LAM y. t2)$s"
end