## The set of ideals on an infinite join-semilattice is a boolean algebra

The below is wrong, because pointfree funcoids between boolean algebras are not the same as 2-staroids between boolean algebras. It was an error. I have just discovered that the set of ideals on an infinite join-semilattice is a boolean algebra (moreover it is a complete atomistic boolean algebra). For me, it is a very counter-intuitive […]