RTL resembles an extremely simple version of a high level programming language, like C. Imagine there is a large one-dimensional integer array called m, and several integer variables called A, PC, etc. The left pointing arrow is just the assignment operator: = in C or := in Pascal and Modula-2 and Ada.

The only expressions that can appear on the left hand side of an RTL statement are those that are permitted by the hardware, namely the functions of the ALU and the shifter. For example, when the binary addition function is used, we will write:

A <- A + TMP