does this mean i can't short?

hi , I'm working on an article in the Artificial Intelligence field that concludes from some testings that markets are not random . but I don't know any fundamentals and I can't understand the below phrase , does this mean that we can't have short positions?

"The trading strategy that we adopt is a one-point buying and selling strategy . this means that all available capital is invested in shares , or all capital is invested in some low risk fixed interest security . on the basis of the trading signal issued by the network , either the low-risk security is sold and shares are bought (buy signal) , or vice-versa(sell signal) . note that shares can only be sold if the investor is currently 'in the market' , and bought if the investor is ' not in the market' " .

thanks

I assume that's what it means. You can't sell unless you already own the shares, which means, no short selling.

Best Regards,

Nader