5. ACCOUNTS RECEIVABLE (Tables)

12 Months Ended

May 31, 2018

Receivables [Abstract]

Accounts receivable

Accounts receivable comprise (in thousands):

	May 31,
	2018			2017
Accounts receivable	$	2,860		$	4,071
Less: Allowance for doubtful accounts		(4	)		(61	)
	$	2,856		$	4,010

			Additions
	Balance at		charged to					Balance
	beginning		costs and					at end
	of year		expenses		Deductions*			of year
Allowance for doubtful accounts receivable:
May 31, 2018	$	61	$	4	$	(61	)	$	4
May 31, 2017	$	8	$	53	$	—		$	61

    * Deductions include write-offs of uncollectible accounts, collections of amounts previously reserved, and releases of allowance for doubtful accounts credited to expense.