The FLOW method of VPGL language has three functions – pass through object, branch flow of object and merge flows of object according to the combination of number of input/output as described below.

Tiles having this method does not display opname and option – only displays input/output arrows for readability of diagrams.

- 1 input – 1 output:

In this case FLOW passes through the object from input 0 to output 0. - 2 input – 2 output:

In this case, FLOW starts at arriving a object on input 0 or input 1, then passes through input 0 to output 0, and input 1 to output 1. (2 indivisual paths) - 1 input – 2 or 3 output:

In this case, FLOW copies of the reference pointer of the object of input 0 as same number as output. If there are 2 output, FLOW makes 2 copies of reference of the object from input 0, then emits each copies to output 0, and output 1. If there are 3 output, FLOW makes 3 copies then emits output 0, 1 and output 2. - 2 or 3 input – 1 output:

In this multiple input and single output case, FLOW starts on arriving one of any input 0, 1 (or 2). FLOW passes through all input to output 0. (merging multiple paths into one).