dylan-lang/opendylan — pull request #775 by waywardmonkeys (2014-06-12 10:00:37+00:00)
Title: [dfmc-modeling] Fix ^known-disjoint? crash with singletons and unions.

We can't check ^known-disjoint? with the value of a singleton as this
may not be a type and ^known-disjoint? is defined on and not