Library Coq.Bool.Sumbool
Here are collected some results about the type sumbool (see INIT/Specif.v)
sumbool A B, which is written {A}+{B}, is the informative
disjunction "A or B", where A and B are logical propositions.
Its extraction is isomorphic to the type of booleans.
A boolean is either true or false, and this is decidable
Logic connectives on type sumbool
Any decidability function in type sumbool can be turned into a function
returning a boolean with the corresponding specification: