if we must argue over the/they, we can just remove the unecessary word
diff --git a/Doc/tut/tut.tex b/Doc/tut/tut.tex
index fc9f573..b00eaea 100644
--- a/Doc/tut/tut.tex
+++ b/Doc/tut/tut.tex
@@ -4405,7 +4405,7 @@
similar to list comprehensions but with parentheses instead of brackets. These
expressions are designed for situations where the generator is used right
away by an enclosing function. Generator expressions are more compact but
-less versatile than full generator definitions and they tend to be more memory
+less versatile than full generator definitions and tend to be more memory
friendly than equivalent list comprehensions.
Examples: