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The <B>size</B> button change the size of the symbols representing points and events.<BR><BR>
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The <B>snap</B> button toggles between free positioning mode and stick-to-grid mode. In the last one, the mouse will tend to stick to the displayed grid lines, if it's close to them. Note that in both modes, clicking close enough to an event symbol or a point does the job. Try and see, it's the best way to understand the mouse behaviour. <BR><BR>
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The <B>proj </B>button provides the most