In Bourne shell builtin(https://www.gnu.org/software/bash/manual/bash.html#Bourne-Shell-Builtins <https://www.gnu.org/software/bash/manual/bash.html#Bourne-Shell-Builtins>), shift command
"Parameters represented by the numbers $# to $#-n+1 are unset." should be "Parameters represented by the numbers $1 to $#-n+1 are unset."
