Quarterly report pursuant to Section 13 or 15(d)

Stock Options and Warrants (Detail)

v3.19.1
Stock Options and Warrants (Detail) - USD ($)
 9 Months Ended 12 Months Ended
Feb. 28, 2019
May 31, 2018
Stock option and warrant activity    
Options and warrants outstanding, Number of Shares 132,385,269  
Granted, Number of Shares 53,394,631  
Exercised, Number of Shares 0  
Forfeited/expired/cancelled, Number of Shares (10,736,262)  
Options and warrants outstanding, Number of Shares 175,043,638 132,385,269
Outstanding exercisable, Number of Shares 171,069,400  
Options and warrants outstanding, Weighted Average Exercise Price $ 0.80  
Granted, Weighted Average Exercise Price 0.58  
Exercised, Weighted Average Exercise Price 0  
Forfeited/expired/cancelled, Weighted Average Exercise Price 0.82  
Options and warrants outstanding, Weighted Average Exercise Price 0.73 $ 0.80
Outstanding exercisable, Weighted Average Exercise Price $ 0.74  
Options and warrants outstanding, Weighted Average Remaining Contractual Life in Years 3 years 10 months 20 days 3 years 9 months 11 days
Outstanding exercisable, Weighted Average Remaining Contractual Life in Years 3 years 9 months  
Options and warrants outstanding, Aggregate Intrinsic Value $ 2,129,223 $ 3,673
Outstanding exercisable, Aggregate Intrinsic Value $ 2,108,816