Y becomes Z

Thanks to Bernd Siebert
https://stacks.math.columbia.edu/tag/021L#comment-8548

Author: aisejohan

CONTRIBUTORS

@@ -454,6 +454,7 @@ Liran Shaul
 Che Shen
 Bryan Shih
 Minseon Shin
+Bernd Siebert
 Jeroen Sijsling
 Lior Silberman
 Carlos Simpson

topologies.tex

@@ -2214,7 +2214,7 @@ \section{The fppf topology}
 
 \begin{lemma}
 \label{lemma-composition-fppf}
-Given schemes $X$, $Y$, $Y$ in $(\Sch/S)_{fppf}$
+Given schemes $X$, $Y$, $Z$ in $(\Sch/S)_{fppf}$
 and morphisms $f : X \to Y$, $g : Y \to Z$ we have
 $g_{big} \circ f_{big} = (g \circ f)_{big}$.
 \end{lemma}