Glyph connector

A glyph connector is the end portion of a glyph part intended to overlap a neighbouring part in a mathematical glyph assembly. An OpenType MATH table gives start and end connector lengths along the extension direction: left/right for a horizontal assembly and bottom/top for a vertical one.^[ref]

Let adjacent parts have full advances $a_1,a_2$, joining connector lengths $c_1,c_2$, and minimum overlap $o_{\min }$. An allowed overlap $o$ must satisfyThe bounds come from the available connector material and minConnectorOverlap.^[ref]

For invented dimensions in font units, choose $a_1=600$, $a_2=500$, $c_1=120$, $c_2=90$ and $o_{\min }=50$. Then $50\le o\le 90$, giving $1010\le L\le 1050$. A target extent 1030 requires overlap 70 and is feasible. A target extent 1000 requires overlap 100, exceeding the second connector's length, so this pair cannot produce it.

These are construction advances, rather than measured ink bounds. Connector data permit controlled changes of extent while other geometry keeps the parts aligned. The mathematical glyph assembly still needs placement relative to the text baseline.