# Summary

A machine word is accessed using the mode `BITS` and a number of operators. A value of mode `BITS` can be denoted using binary, quaternary (radix 4), octal or hexadecimal digits. Names which refer to names form the basis of self-referential modes (via `STRUCT` and `REF`) from which we can construct queues and trees. Some of the basic procedures were covered which manipulate these data structures.