-- | Merge two SOP terms by additions
mergeSOPAdd :: (Ord v, Ord c) => SOP v c -> SOP v c -> SOP v c
mergeSOPAdd (S sop1) (S sop2) = simplifySOP $ S (sop1 ++ sop2)
mergeSOPAdd :: (Ord v, Ord c) => SOP v c -> SOP v c -> SOP v c
mergeSOPAdd (S sop1) (S sop2) = simplifySOP $ S (sop1 ++ sop2)
mergeSOPAdd (S sop1) (S sop2) = simplifySOP $ S (sop1 ++ sop2)