Income Taxes (Details 1) - USD ($)	May 31, 2020	May 31, 2019
Income Tax Disclosure [Abstract]
Basis difference of assets	$ 162,853	$ 182,654
Inventory related items	75,500	169,585
Other reserves and liabilities	112,829	74,694
Net operating loss carryforward	624,650	1,507,141
General business and other credit carryforward	455,841	489,327
Other deferred items, net	0	7,692
Gross deferred tax assets	1,431,673	2,431,093
Deferred tax asset valuation allowance	(1,431,673)	(2,431,093)
Net deferred tax assets	$ 0	$ 0