The structure: +-----+ +-----+ | A | | B | +-----+ +-----+ | | +-----+ +---+ +---+ | C |----| |-------| | +-----+ +---+ +---+ | +-----+ +---+ | D |----------------| | +-----+ +---+ One way to show it on the screen: +-----+ | A | +-----+ --o /| / +-----+ | C | +-----+ \ \| --o +-----+ | B | +-----+ Another: +-----+ | A | +-----+ --o /| +-+ +-+ / +-----+ | C | +-----+ \ +-+ +-+ \| --o +-----+ | B | +-----+ Here, the empty boxes in the arrows are the link cells from the first picture, above. All this was for a single representation in the structure. Here's an alternative way to represent this in zzstructure: +-----+ +-----+ +-----+ +-----+ | A | | B | | C | | D | +-----+ +-----+ +-----+ +-----+ | | | +---+ | +---+ | | |-------------------| | | +---+ | +---+ | | | | +---+ +---+ | | |-------| | | +---+ +---+ | | | +---+ +---+ | |-------------------| | +---+ +---+