add some utility methods for dealing with true/false
minor refactor
imports
spec static member refs
more xrefs
minor
minor
xrefs
xref
do the TODO
mention static refs
improve error message
initial work on new solution to #596 based on Ross's idea about "shapes"
update decidability tests for new algorithm
fix impl of rule 3
fix tests, given new rules
finishing fixing tests for new rules
types with self type may not inherit other parameterized types
fix minor bug
Merge branch '596' of github.com:ceylon/ceylon-spec into 596