useRule :: Rule -> Interval -> ([Interval], [Interval], [Rule])
useRule (Rule (Iv rl rh) d) (Iv xl xh) = (newResults, newVals, newRules)
where newResults =
useRule :: Rule -> Interval -> ([Interval], [Interval], [Rule])
useRule (Rule (Iv rl rh) d) (Iv xl xh) = (newResults, newVals, newRules)
where newResults =