InfoPath 2010 validating rules for multiple check boxes

I have a check box in an InfoPath form, that when checked, at least 1 of these other 18 check boxes have to be checked as well before submitting. However, it appears I can only add 5 conditional statements to a validating rule. When I tr开发者_JS百科y to add a validating rule to one of the 18 check boxes, I can only enter in 5 of the remaining 17 check boxes.

What I want is if the original check box is checked, I would like the form to submit only if at least 1 of the other 18 boxes is checked as well. Any ideas?

By using a custom expression in the Validating rules for the check box, I was able to accomplish this.

not((../my:field2 | ../my:field3 | ../my:field4 | ../my:field5 | ../my:field6)[. = "true"])