What is exactly is trial and error warfare?

Print "usernum1 is negative." if usernum1 is less than 0. end with newline. convert usernum2 to 0 if usernum2 is greater than 10. otherwise, print "usernum2 is less than or equal to 10.". end with newline

All of the following are characteristics that must be contained in any knowledge representation scheme except

Arecipients list has been loaded into a document. which commands should be clicked in order to filter the list so that letters will not be printed for recipients who live in a certain state? mailings tab, start mail merge, select recipients, type new list, then insert only contacts from the desired states mailings tab, rules, select recipients, use existing list, then choose a recipients list that includes only contacts in certain states mailings tab, select recipients, use existing list, rules, fill in, then type in certain states mailings tab, rules, skip record select “state” under field name, then type in the state name under “equal to”