úÎø Safe-InferredAn  group is a  that follows the rule: a < > b == b <> aA  is a  plus a function, , such that:  a <> invert a == mempty  invert a < > a == mempty       groups-0.3.0.0 Data.GroupAbelianGroupinvertbase Data.MonoidMonoid$fAbelian(,,,,)$fAbelian(,,,) $fAbelian(,,) $fAbelian(,) $fAbelian(->) $fAbelianDual$fAbelianProduct $fAbelianSum $fAbelian() $fGroup(,,,,) $fGroup(,,,) $fGroup(,,) $fGroup(,) $fGroup(->) $fGroupDual$fGroupProduct $fGroupSum $fGroup()