The structured assembly language for the General ElectricCompany 4xxx range of computers and their OS4000 operatingsystem. It is strictly an assembler in that the generated

code is relatively predictable but it can be written in a

sufficiently structured manner, with indentation, control

statements, function and procedure calls, to make the

resultant source easy to read and manage. Even with this

visible structure however, it is important to remember that

the assembly of the statement is done left to right.