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In this tutorial we are going to use a set of reusable components that have been prepared in advance.
Preparation: Download a zipped folder containing the components  from here, unzip the folder and save it to a desired place on your computer. Open the folder in a file browser.

1. Open a new document.
2. Drag the file named start.svg from the file browser and drop it onto the canvas.
3. Drag the file named procedure.svg and drop it onto the canvas. Drag the free point (green) at the top of the procedure component toward the point variable at arrow tip of the start component and release the mouse button when the cursor changes into cross-hairs. Observe that the two point variables become one. This is referred to as snapping.
4. Click on the text "Procedure" and in the constraint field change the text to "Open file".
5. Drag and drop the file named input.svg onto the canvas and snap it into place. Change the text in the component to "Read record".
6. Drag and drop the file named condition.svg onto the canvas and snap it into place. Change the text in the component to "End of file?".
7. Drag and drop the file named procedure.svg onto the canvas and snap it to the "No" branch. Change the text in the component to "Process record".
8. Drag and drop the file named procedure.svg onto the canvas and snap it to the "Yes" branch. Change the text to "Close file".
9. Drag and drop the file named end.svg onto the canvas and snap it into place below the end of the "Close file" component.
10. Drag and drop the file named input.svg onto the canvas and snap it into place below the "Process record" component. Change the text to "Read record".
11. Drag and drop the file named hvh-connector.svg (hvh = horizontal-vertical-horizontal) onto the canvas. Snap the free point variable that is not at the arrow tip to the bound point variable at the arrow tip below the "Read record" component. Snap the free point variable at the arrow tip of the hvh-connector to the line segment above the "End of file?" component. This causes a colinear constraint to be added to the point variable.
12. Make smaller adjustments by dragging the points that have at least one degree of freedom (DOF).
13. Save the document.