(lorem ipsum dolor sit amet)

✖ ERROR: Variable IPSUM is not bound.

(loop for x from 0 to 19 if (oddp x) do (format t "~D " x) else collect x)

▷ 1 3 5 7 9 11 13 15 17 19

→ (0 2 4 6 8 10 12 14 16 18)

(setf (first '(1 2 3 4)) 'one)

? The above has undefined consequences.

(loop for x from 0 to 19 if (oddp x) do (format t "~D ~%" x) else collect x) ; ⟦foo⟧

▷ 1 3 5 7 9 11 13 15 17 19