Structure Control Language (SCL) is ideally suited for the complex algorithm programming and complex data processing in PLC. The structure of SCL source files is introduced in detail. Taking the ...

Backtracking is a well-known technique for solving combinatorial problems. It is of interest to programming methodologists because 1) correctness of backtracking programs may be difficult to ascertain ...

Some have to do with flow of control (control structures), while others control access to variables (environment structures). Some of these features are implemented as special forms; others are ...