zoodle

I need a little help understanding this tutorial: https://digilent.com/reference/programmable-logic/guides/getting-started-with-ipi Just over a third of the way down the page the tutorial starts talking about the AXI GPIO IP. This sentence has me lost: I do not understand where this naming is coming from ("As can be seen"). On the diagram the AXI GPIO ports are labelled gpio_io_i, gpio_io_o and gpio_io_t. I cannot find any reference to ***_tri_io. Any pointers appreciated!