Code in triggers

[badanov 115]

I have a trigger that has two conditions to be met at the time the trigger is read;

 

missetXC1=="CON10" AND XC1 where missetXC1 is a mission, n this case an attack mission, and the selection "CON10"; The second part is the actual mission set identified XC1;

If the condition is read at the time of trigger invocation, I should be moved to "CON10", which is the 10th mission out of a set of X number of missions under XC1 which is mission set 1.

As I understand it, in this case both AND and && are correct in passing these kinds of condition, correct?

 

Now, if I change the condition to: this; missetXC1=="CON10"; XC1; it works as well;

 

I have two questions, which is better, more efficient in terms of CPU resources?

Why would the game be displaying errors in the first instance about boolean code and strings, but still work, while continually displaying the errors?

 

BTW, dunno if this is the right forum to ask these questions. If not sorry.