Definition 37.6.1. Let f : X \to S be a morphism of schemes. We say f is formally unramified if given any solid commutative diagram
\xymatrix{ X \ar[d]_ f & T \ar[d]^ i \ar[l] \\ S & T' \ar[l] \ar@{-->}[lu] }
where T \subset T' is a first order thickening of affine schemes over S there exists at most one dotted arrow making the diagram commute.
Comments (0)