Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Feb. 28, 2025	Feb. 29, 2024
Operating activities
Net income	$ 5,725,060	$ 6,526,132
Adjustments to reconcile net income to net cash flows from operating activities
Depreciation	1,386,620	1,341,435
Amortization	16,668	1,852
Stock options issued for services	731,204	301,308
Changes in other assets and liabilities
Accounts and other receivables, net	(1,504,248)	666,879
Inventory	(943,946)	(1,094,260)
Costs and estimated earnings in excess of billings	1,126,813	(409,837)
Other current assets	(1,476,833)	203,809
Accounts payable	(324,137)	(761,816)
Accrued expenses	3,206,098	(38,331)
Billings in excess of costs and estimated earnings	(2,368,711)	(32,184)
Other assets	(38,077)	(27,343)
Net operating activities	5,536,511	6,677,644
Investing activities
Acquisition of property and equipment	(1,157,996)	(755,339)
Patent expenditures	0	(300,000)
Purchase of short-term investments	(11,504,432)	(7,553,133)
Proceeds from sale of short-term investments	6,500,000	10,500,000
Other investing activities	(3,531)	(3,588)
Net investing activities	(6,165,959)	1,887,940
Financing activities
Proceeds from issuance of common stock, net	239,954	443,513
Acquisition of treasury stock	(140,273)	(9,527,866)
Net financing activities	99,681	(9,084,353)
Net change in cash and cash equivalents	(529,767)	(518,769)
Cash and cash equivalents - beginning	2,831,471	3,575,219
Cash and cash equivalents - ending	$ 2,301,704	$ 3,056,450