isOnImage(W, p)
isOnImage(F, I, p)
This method determines if a point in the ambient target space lies on the image of a variety. This is done via computing a pseudo-witness set for the image.
If a pseudo-witness set has already been computed, then to avoid repetitive calculation one may run this function with the pseudo-witness set as input.
The following example determines whether a point lies on the Grassmannian $Gr(2,4)$ of $P^1$'s in $P^3$, under its Plücker embedding in $P^5$.
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The object isOnImage is a method function with options.