Meaning of symbol similar to $\not >$ in front of a matrix

Question

I found the following symbol in a paper about rotations using quaternions:

The paragraph appears at the beginning of page 635 in Closed-form solution of absolute orientation using unit quaternions by Berthold K. P. Horn.

Does it have any special meaning? What does it refer to?

Answer 1

After revising the paper once and again, my conclusion is that $\not >\mathbb{R}_{l,i}$ and $\bar{\mathbb{R}}_{l,i}$ (last matrix in page 634) are the same. Thus it seems to be just a matter of notation; maybe some Latex problem due to inline math coding.

Answer 2

If it were $A \not\gt B$, it probably means "not strictly positive", which for a matrix is NOT equivalent to $\leq$ (for a real number, $x \not\gt 0 \leftrightarrow x \leq 0$). So $A \not\gt B$ means $A - B$ is not a positive definite (p.d.) matrix.

But on the paper you cited, I have no idea what it could mean, sorry.