+ = elt { tct_co = Rigid (WpCo co' <.> co), tct_type = ty' }
+ refine elt@(ATcId { tct_co = Wobbly})
+-- Main new idea: make wobbly things invisible whenever there
+-- is a refinement of any sort
+-- | otherEquations
+ = elt { tct_co = WobblyInvisible}