Income Taxes (Tables)
 12 Months Ended
May 31, 2018
Income Tax Disclosure [Abstract]  
Provision for Income Taxes

The provision for income taxes is as follows:

 

     Year ended May 31,  
     2018      2017      2016  

Current

    $ 25,915      $ 28,009      $ 20,002  

Deferred

      808,548        (356,169 )       (533,357 ) 

Change in valuation allowance

      (808,548 )       356,169        533,357  
  

 

 

     

 

 

     

 

 

  

Total provision for income taxes

    $ 25,915      $ 28,009      $ 20,002  
  

 

 

     

 

 

     

 

 

  
Components of Deferred Tax Assets

Deferred tax assets are comprised of the following components:

 

     2018     2017  

Basis difference of assets

    $ 202,763     $ 307,846  

Inventory related items

      189,893       287,543  

Other reserves and liabilities

      87,519       122,083  

Net operating loss carryforward

      1,136,358       1,723,418  

General business and other credit carryforward

      456,343       449,048  

Other deferred items, net

      29,182       20,667  
  

 

 

    

 

 

  

Gross deferred tax assets

      2,102,058       2,910,605  

Deferred tax asset valuation allowance

      (2,102,058 )      (2,910,605 ) 
  

 

 

    

 

 

  

Net deferred tax asset

    $ 0     $ 0  
  

 

 

    

 

 

  
Reconciliation of Provision for Income Taxes from Amount of Income Taxes of U.S. Statutory Federal Tax Rate to Pre-Tax Loss

The provision for income taxes differs from the amount of income taxes determined by applying the U.S. statutory federal tax rate to pre-tax loss due to the following:

 

     Year ended May 31,  
     2018     2017     2016  

Statutory federal tax rate

      28.6 %      (34.0 )%      (34.0 )% 

State taxes, net of federal benefit

      2.6       (4.4 )      (4.4 ) 

Change in deferred tax valuation allowance

      (350.8 )      34.1       35.7  

Impact of Tax Act

      329.8       0.0       0.0  

Stock-based compensation

      6.6       2.2       1.2  

R&E tax credits

      1.6       1.6       0.7  

Effect of foreign income tax rates

      1.3       (0.3 )      1.1  

Deferred tax true-up

      (12.6 )      1.8       0.3  

State minimum taxes

      5.1       1.1       0.4  

Permanent and other differences

      (1.2 )      0.6       0.3  
  

 

 

    

 

 

    

 

 

  

Effective tax rate

      11.0 %      2.7 %      1.3 %