¹ This concept is simpler to implement than it first seems. Assume, for example, that each transputer associates the same memory location 10 with the variable _node_number. Since each transputer has its own private memory, the loader, when it initializes the chain of transputers, can instruct the root transputer to store the number 1 at address 10 in its local memory, and to pass 1+1=2 to its child, which stores that number in its own local memory, at address 10, and then passes 2+1=3 to its own child, and so on. This way, when a transputer tests the contents of _node_number, the action of testing the contents of address 10 in the local memory results in different number depending on which transputer is performing the test. More precisely, it must be included everytime we use non-ANSI C statements relating to multitasking or channel I/O.