Composite reactions, in which processes like \[\rm{A}\ \overset{1}{\rightarrow }\ \rm{Y}\] and \[\rm{B}\ \overset{2}{\rightarrow }\ \rm{Z}\] occur in parallel, can be called simultaneous or parallel reactions. Sometimes there is competition involved, like in the scheme: \[\rm{A}\,+\,\rm{B}\ \overset{1}{\rightarrow }\ \rm{Y}\] and \[\rm{A}\,+\,\rm{C}\ \overset{2}{\rightarrow }\ \rm{Z}\] where B and C compete with one another for A.