ad="Ok"
a="Ba"

# "Ok"
echo $a\
d

# This variable contains backslash+newline!
e='echo $a\
d'

# "Ba d"
eval $e
# "Ok"
eval "$e"

echo $\
(echo Ok\
)
echo "$\
(echo Ok\
)"

echo Forty two:$\
(\
(\
42\
)\
)
echo "Forty two:$\
(\
(\
42\
)\
)"