Bilinkage in codimension 3 and canonical surfaces of degree 18 in mathbb{P}⁵

We study the behavior of the bilinkage process in codimension $3$. In particular, we construct a smooth canonically embedded and linearly normal surface of general type of degree $18$ in $\mathbb{P}^5$, this is probably the highest degree such surface may have. Next, we apply our construction to find a geometric description of Tonoli Calabi--Yau threefolds in $\mathbb{P}^6$.