connector for defining reaction or product groups in reaction schemes
A subclass of RSreac, though not strictly a reaction at all, RSpoolPlus allows pools to be "added" as the products or reactants of RSreac reactions. For example, in the reaction A + B + C <--> D + E, A and B would be linked with a RSpoolPlus link, as would B and C and D and E. C and D would be linked by the reaction itself.
Look at the ReactionScheme interface to see how this works in practice - it amounts to dragging RSpolPlus reactions to take the place of "+" signs and a real reaction for the equilibrium sign. For reactions of the form A + B <--> C, the plusRSreac provides a more convenient, but functionally equivalent, shortcut to this process.