The following pages are from Lee's "Introduction to Smooth Manifolds".
Is $dF(T_{(p,s)}W)=T_qX$ in the red rectangle a typographical error?
Should $dF(T_{(p,s)}W)=T_qX$ be changed to $dF(T_{(p,s)}W)\subset T_qX$?
The following pages are from Lee's "Introduction to Smooth Manifolds".
Is $dF(T_{(p,s)}W)=T_qX$ in the red rectangle a typographical error?
Should $dF(T_{(p,s)}W)=T_qX$ be changed to $dF(T_{(p,s)}W)\subset T_qX$?
You're right, this is a mistake, and it's repeated further down the page. (Actually, it's more of a logical oversight than a typographical error.) I've added both corrections to my online list.
Thanks for pointing this out.