Page "Flat morphism" Paragraph 46

* Assume f is flat at x in X.

If X is reduced or normal at x, then Y is reduced or normal, respectively, at f ( x ).< ref > EGA IV < sub > 2 </ sub >, Proposition 2. 1. 13 .</ ref > Conversely, if f is also of finite presentation and f < sup >− 1 </ sup >( y ) is reduced or normal, respectively, at x, then X is reduced or normal, respectively, at x .< ref > EGA IV < sub > 3 </ sub >, Proposition 11. 3. 13 .</ ref >