Question about pseudo code

Hi, I think Strategyquant is one of  the most interesting programs I have come across in a long time. I have a question about the generated pseudo code. It typically looks like this:

//——————————————————————–
// Trading rule: Long entry (On Bar Open)
//——————————————————————–
if LongEntrySignal
{
   // Action #1
}

//——————————————————————–
// Trading rule: Short entry (On Bar Open)
//——————————————————————–
if (ShortEntrySignal
and Not LongEntrySignal)
{
   // Action #1
}

Does it make a difference that ShortEntrySignal checks there is no LongEntrySignal but LongEntrySignal does not check there is no ShortEntrySignal?

Thanks.

Both trading signals for long and short should never be valid at the same but in case it happens the long signal will be executed