(randLine,subsLine) = randomLine(point,J,relPfaf,Sa)(randLine,subsLine) = randomLine(point,relPfaf,Sa)The procedure computes a line in the $\mathbb{P}^{11}$ given by the polynomial ring $S_a$. This lines contains the given point and is completely contained in the variety of the 4 quadratic relations in $\mathbb{P}^{11}$. If an second ideal $J$ is given as an argument, the line will intersect the vanishing locus $V(J)$, if possible. The line is represented by a $12\times 2$ matrix whose first column parametrize the given first point and whose second column represents either a general point on the line or a point in the variety $V(J)$. The row matrix "subsLine" contains all variables of the construction with the $a$-variables replaced by the assignment obtained from the chosen line.
The object randomLine is a method function.