The Sequence multi-line details view is used to show sequence in a few rows.
To use it click the Wrap sequence button:
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After that the sequence will be divided into several parts. The width of the parts is enough for fitting into the sequence area. The multi-line mode is often more convenient than single-line, because, in this case, the analysis of a sequence is like working with a text in a text editor. Information is shown left-to-right, up-to-down.
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Click the button Wrap sequence again to switch the mode off.