>A set has closure under an operation(s) if using those operations on the set members always gives you a member in the same set. THANK YOU. That line was key a

>A set has closure under an operation(s) if using those operations on the set members always gives you a member in the same set. THANK YOU. That line was key and just clicked for me. I'm actually liking everyone's completely-different ways of explaining the same things. When one, or five, are confusing, the sixth may be key to filling in the holes.