Derivative Liabilities (Tables)

12 Months Ended

Jul. 31, 2017

Notes to Financial Statements

Derivative warrant liability

	Value			No. of Warrants
Balance at July 31, 2015 - Derivative warrant liability	$	2,363,415			512,911
Forfeited or expired		(455,573	)		(129,033	)
Increase in fair value of derivative warrant liability		141.004			n/a
Balance at July 31, 2016 - Derivative warrant liability		2,048,846			383,878
Forfeited or expired		(240,906	)		(65,896	)
Warrants exercised		(1,532,336	)		(317,982	)
Decrease in fair value of derivative warrant liability		(275,604	)		n/a
Balance at July 31, 2017 - Derivative warrant liability	$	—			—

Fair value assumptions, derivative warrant liability

	July 31, 2016
Current exercise price	$	15.00
Time to expiration		2.1 years
Risk-free interest rate		0.76	%
Estimated volatility		101	%
Dividend		—
Stock price at year end	$	8.00

Fair value assumptions, derivative additional investment rights liability

	July 31, 2016
Underlying number of units of convertible preferred stock		500
Underlying number of units of warrants		33,333
Current exercise price of warrants	$	15.00
Current conversion price of preferred stock	$	15.00
Time to expiration		0.05 years
Risk-free interest rate		0.38	%
Estimated volatility		13	%
Dividend		-0-
Stock price at year end	$	8.00