act ins10, ins20, acc10, acc20, coin10, coin20, ret10, ret20 ; optA, optC, chg10, chg20, putA, putC, prod, readyA, readyC, out10, out20 ; proc User = *1* Mach = acc10.( putA.prod + acc10.( putC.prod + ret20 ) + ret10 ).Mach + acc20.( putA.prod.ret10 + putC.prod + ret20 ).Mach ; init *2* ;