4.1 Phy-dig-world illustration

Illustrated examples:

1. The bi-directional learning/inspiring between physical, digital, and mixed world
2. the parallel and mixed promoting of three worlds

1. The bi-directional learning/inspiring between physical, digital, and mixed world

Three worlds inspire each other

2.  the parallel and mixed promoting of three worlds

The development of three worlds could be parallel, and preferably parallel. Moreover, the development of each one affects the other two