What does it mean for the integral to have a lower limit, but no upper limit?
Is there a difference between having [for example] the lower limit directly below the integral sign, rather than slightly in front?
I've seen multiple integral signs next to each other, and there is what appears to be a single lower limit for _all_ of them (this 'lower limit' is centered along the bottom, of these signs). Does this just mean the 'nth' integral of y, with a lower limit of 'whatever' ?
I've also seen integral signs with circles on their 'belly' (I think I made that term up... I'm sure you know what I mean though). What does this mean? What does it mean for a group of integral signs to be 'sharing' one of these circles ?
...I think I read something about it meaning the magnitude of the result -- so, the positive value.. or something.. ?