wait

wait { {for time-expression} | 
	{until truth-value-expression checking every time-expression} | 
	{until {variable | parameter | {the attribute-name [local-name] of item} |
	{the {class-name | type} that is an attribute of item [named by 
	symbolic-expression] } 	receives a value}	

repeat 
	exit if the temp of tank-1 > the high-limit of tank-1; 
	wait until the temp of tank-1 receives a value or 
	    the high-limit of tank-1 receives a value; 
end