INCOME TAXES (Details) - USD ($)	12 Months Ended
	May 31, 2021	May 31, 2020
INCOME TAXES (Details) [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%
Deferred Tax Assets, Valuation Allowance	$ 5,904,000	$ 3,612,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	2,292,000	1,152,000
Equity Option [Member]
INCOME TAXES (Details) [Line Items]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ 437,000
Domestic Tax Authority [Member]
INCOME TAXES (Details) [Line Items]
Operating Loss Carryforwards	12,957,000
California State Income Tax [Member]
INCOME TAXES (Details) [Line Items]
Operating Loss Carryforwards	6,768,000
Research Tax Credit Carryforward [Member] | Domestic Tax Authority [Member]
INCOME TAXES (Details) [Line Items]
Tax Credit Carryforward, Amount	715,000
Research Tax Credit Carryforward [Member] | State and Local Jurisdiction [Member]
INCOME TAXES (Details) [Line Items]
Tax Credit Carryforward, Amount	$ 341,000