INTANGIBLE ASSETS, NET (Tables)

12 Months Ended

May 31, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Finite-Lived Intangible Assets [Table Text Block]

	2021		2020
Licenses	$	182,176	$	551,397
Patents		239,423		113,382
Less accumulated amortization-licenses		(107,194)		(487,989)
Less accumulated amortization-patents		(19,575)		(8,135)
Intangible asssets, net	$	294,830	$	168,655

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

2022	$	21,846
2023		20,058
2024		20,058
2025		19,071
2026		18,975
Thereafter		194,822
Total	$	294,830