PC = PC+1; fetch     // start fetching varnum2  (fetching of varnum1 performed by Main1)
OPC = MBRU           // opc <-- varnum1
H = LV
MAR = MBRU+H; rd     // start reading M[LV + varnum2]
PC = PC+1; fetch     // start fetching varnum3
TOS = MDR            // tos <-- M[LV + varnum2]
MAR = MBRU+H; rd     // start reading M[LV + varnum3]
H = TOS              // H <-- M[LV + varnum2]
MDR = MDR+H          // MDR <-- M[LV + varnum2] + M[LV + varnum3]
H =LV
MAR = OPC+H; wr      // start writing M[LV + varnum2] + M[LV + varnum3] in M[LV + varnum1]
PC = PC+1; fetch;goto Main1   // start fetching next opcode and go to beginning of interpreter
Main1 GOTO (MBR)