Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Feb. 29, 2024	Feb. 28, 2023
Operating activities
Net income	$ 6,526,132	$ 4,220,766
Adjustments to reconcile net income to net cash flows from operating activities
Depreciation	1,341,435	1,003,924
Amortization	1,852	0
Stock options issued for services	301,308	128,437
Changes in other assets and liabilities
Accounts and other receivables, net	666,879	(4,096,679)
Inventory	(1,094,260)	414,140
Costs and estimated earnings in excess of billings	(409,837)	(437,513)
Other current assets	203,809	(113,378)
Accounts payable	(761,816)	40,323
Accrued expenses	(38,331)	(134,605)
Billings in excess of costs and estimated earnings	(32,184)	315,233
Other assets	(27,343)	0
Net operating activities	6,677,644	1,340,648
Investing activities
Acquisition of property and equipment	(755,339)	(2,382,514)
Patent expenditures	(300,000)	0
Purchase of short-term investments	(7,553,133)	(18,179,193)
Proceeds from sale of short-term investments	10,500,000	0
Other investing activities	(3,588)	(3,624)
Net investing activities	1,887,940	(20,565,331)
Financing activities
Proceeds from issuance of common stock, net	443,513	91,492
Acquisition of treasury stock	(9,527,866)	0
Net financing activities	(9,084,353)	91,492
Net change in cash and cash equivalents	(518,769)	(19,133,191)
Cash and cash equivalents - beginning	3,575,219	22,517,038
Cash and cash equivalents - ending	$ 3,056,450	$ 3,383,847