-- | A goal reason is mostly just a variable paired with the
-- decision we made for that variable (except for user goals,
-- where we cannot really point to a solver variable). This
-- function drops the decision and recovers the list of
-- variables (which will be empty or contain one element).
--
goalReasonToVars :: GoalReason qpn -> [Var qpn]
goalReasonToVars UserGoal                 = []
goalReasonToVars :: GoalReason qpn -> [Var qpn]
goalReasonToVars UserGoal                 = []
goalReasonToVars UserGoal                 = []