The following are instructions of the virtual intermediate machine (cmd language) with variables y,x1,x2,y1,y2:

• CmdAssert(x) asserts that x!=0 should hold at this place.
• CmdCopy(y,x) denotes the assignment y := x.
• CmdSglAssign(y,x1,op2,x2) denotes the assignment y := x1 op2 x2 with a binary operator op2.
• CmdDblAssign(y1,y2,x1,op2,x2) denotes the assignment y1,y2 := x1 op2 x2 with a binary operator op2. The rhs is evaluated in full precision and y1@y2 is seen as a double machine word.
• CmdAccessArr(y,x1,x2) denotes y = x1[x2].
• CmdAssignArr(y,x1,x2) denotes y[x1] = x2.
• CmdAssignCnd(y,c,x1,x0) is a conditional assignment y = (c?x1:x0).
• CmdGoto(i) denotes goto(i).
• CmdIfGoto(x,i) denotes if(x) goto(i).
• CmdReturn(x) denotes return(x).
• CmdSync instructs the tread to wait until its writes to the shared variables have been made visible to the other threads.

Hence, all expressions make use of at most one operator, and therefore, we have to abbreviate intermediate expressions by temporary variables. Moreover, function calls have to be inlined since there is no means for the latter. Still, there can be threads of cmd language instructions, with the same shared variables.